A BNVO / VC MXene / RGO photothermal piezocatalytic material, a preparation method and application thereof

Abstract

The application provides a Bi x Nd y VO4 / V4C3 MXene / RGO photo-thermal piezoelectric catalytic material, a preparation method and application thereof, and the photo-thermal piezoelectric catalytic material is a Bi x Nd y VO4 / V4C3 MXene / RGO material, wherein x:y = 1:(0.5-0.75). The preparation method comprises the following steps: S1, mixing a dispersion liquid of multi-layer V4C3 MXene and a dispersion liquid of graphene oxide, and adding a bismuth source and a neodymium source, and stirring to obtain a reaction precursor liquid; S2, performing a hydrothermal reaction on the reaction precursor liquid, and washing and drying the obtained product to obtain a BNVO / VC MXene / RGO photo-thermal piezoelectric catalyst. The Bi x Nd y VO4 / V4C3 MXene / RGO material improves the reduction stability of the material and the selectivity of dark / photothermal carbon dioxide hydrogenation reduction to generate methane.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of environmental protection and solar functional material composite, and particularly relates to a Bi x Nd y VO4 / V4C3 MXene / RGO (abbreviated as BNVO / VC MXene / RGO) photo-thermal piezoelectric catalytic material, a preparation method and application thereof. BACKGROUND

[0002] CH4 is an ideal derivative of CO2 reduction, which can be used as fuel, can be synthesized into ammonia and methanol, can be used as a green hydrogen carrier, and is an important raw material for maintaining life on the international space station and Mars. However, the CO2 methanation reaction process must be operated at very high temperature (300-500 DEG C) and pressure (4-30 bar) conditions, and a rare and expensive supported ruthenium and palladium catalyst must be used to obtain a high conversion rate and reaction rate, therefore, it is urgent to develop a high-performance and environmentally friendly Sabatier CO2 methanation process. SUMMARY

[0003] In order to solve the problems of the prior art, the application provides a Bi x Nd y VO4 / V4C3 MXene / RGO photo-thermal piezoelectric catalytic material, a preparation method and application thereof, which utilizes the Bi x Nd y VO4 / V4C3 MXene / RGO material piezoelectric effect to accelerate carrier separation and migration, and the Bi x Nd y VO4 up-conversion effect makes more high-energy photons participate in the CO2 methanation reaction, improves the reduction stability of the material, and improves the selectivity of dark / photothermal carbon dioxide hydrogenation reduction to generate methane.

[0004] The application is achieved by the following technical scheme:

[0005] A BNVO / VC MXene / RGO photo-thermal piezoelectric catalytic material, the photo-thermal piezoelectric catalytic material is a composite of Bi x Nd y VO4, V4C3 MXene and RGO, wherein x:y = 1:(0.5-0.75).

[0006] The preparation method of the BNVO / VC MXene / RGO photo-thermal piezoelectric catalytic material comprises the following steps:

[0007] S1, mixing a dispersion liquid of multi-layer V4C3 MXene and an oxidized graphene dispersion liquid, and adding a bismuth source and a neodymium source, stirring to obtain a reaction precursor liquid;

[0008] S2, performing a hydrothermal reaction on the reaction precursor solution, and washing and drying the obtained product to obtain the BNVO / VC MXene / RGO photothermal piezoelectric catalyst.

[0009] Preferably, in S1, the preparation method of the multilayer V4C3 MXene is: etching V4AlC3 with an HF solution, and then washing with water and drying to obtain the multilayer V4C3 MXene.

[0010] Preferably, in S1, the molar ratio of the multilayer V4C3 MXene to the graphene oxide in the reaction precursor solution is (2.5-3.08):1.

[0011] Preferably, in S1, the bismuth source and the neodymium source are Bi(NO3)3·5H2O and Nd(NO3)3·6H2O, respectively.

[0012] Preferably, in S1, the molar ratio of Bi:Nd is 1:(0.5-0.75).

[0013] Preferably, in S1, the molar ratio of the bismuth source to the multilayer V4C3 MXene is (0.11-0.24):1.

[0014] Preferably, in S2, the temperature of the hydrothermal reaction is 180-200℃, and the time is 16-18h.

[0015] Preferably, in S2, the drying temperature is 60-70℃, and the time is 10-12h.

[0016] The application also provides the application of the BNVO / VC MXene / RGO photothermal piezoelectric catalytic material in catalyzing the hydrogen reduction of carbon dioxide to produce methane.

[0017] Compared with the prior art, the application has the following beneficial effects:

[0018] The application provides a Bi x Nd y VO4 / V4C3 MXene / RGO piezoelectric catalytic material, the photothermal piezoelectric catalytic material is a composite of Bi x Nd y VO4, V4C3 MXene and RGO, Nd is doped in the BiVO4 crystal lattice to form Bi x Nd y VO4, Bi x Nd y VO4 is grown on the surface and interlayer of the V4C3 MXene to form Bi x Nd yThe VO4 / V4C3 MXene / RGO heterojunction interface electric field. The Nd element doped in BiVO4 can act as an electron or hole trapping agent, reduce the recombination rate of carriers in BiVO4, thereby improving the separation efficiency, and then promoting the progress of the photocatalytic reaction; in terms of light absorption, Nd has a unique electronic structure, which can cause upconversion characteristics, that is, the process of absorbing light with a longer wavelength (lower energy) and releasing light with a shorter wavelength (higher energy), realizing efficient use of light energy. Therefore, the upconversion mechanism of Nd can promote the generation of more high-energy photons by light excitation. At the same time, under the action of the polarization electric field formed by the Schottky junction, the V4C3-MXene surface plasmon effect and the RGO piezoelectric effect, the carriers effectively migrate, and the enriched electrons participate in the CO2 methanation reaction, thereby improving the stability of the V4C3-MXene matrix material and the conversion rate of the catalytic reduction of carbon dioxide and the selectivity of methane generation, realizing the Bi x Nd y VO4 / V4C3 / RGO piezoelectric catalytic material further improves the content of methane generated by catalytic hydrogenation reduction in a dark / light thermal environment.

[0019] The Bi x Nd y VO4 / V4C3 MXene / RGO piezoelectric catalytic material has piezoelectric properties, d 33 0.41nm V -1 , and the material stores 112.9μmol g -1 electrons and 172.9μmol g -1 holes, and the proportion of the upconversion effect of Nd in the total activity is R=3.01%, Nd doping can generate more photoelectrons, promote the photo-thermal reduction of CO2 methanation, and has the characteristics of catalyst stability and high methane yield in dark / light thermal catalytic reduction, and therefore can be applied in the field of catalytic hydrogenation reduction of carbon dioxide to produce methane. The Bi x Nd y VO4 / V4C3 MXene / RGO piezoelectric catalytic material is used for dark / light thermal hydrogenation reduction of carbon dioxide to produce methane, which improves the content of methane generated by photo-thermal reduction of the V4C3 MXene-based catalytic material, and the test shows that the methane yield in a light thermal environment is as high as 229.9μmol·g -1 ·h -1 , which is 2.3 and 10.6 times higher than that of BiVO4 / V4C3 / RGO and Bi x Nd y VO4 catalysts, respectively. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the accompanying drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0021] Figure 1 BiVO4 / V4C3 MXene / RGO prepared for the present application x Nd y XRD pattern of the VO4 / V4C3 MXene / RGO material;

[0022] Figure 2 BiVO4 / V4C3 MXene / RGO prepared for Example 2 x Nd y SEM pattern of the VO4 / V4C3 MXene / RGO;

[0023] Figure 3 BiVO4 / V4C3 MXene / RGO prepared for Comparative Example 3 x Nd y SEM pattern of the VO4;

[0024] Figure 4 BiVO4 / V4C3 MXene / RGO prepared for Example 2 x Nd y Absorbance curve of the BiVO4 / V4C3 MXene / RGO in degrading methylene blue under dark conditions;

[0025] Figure 5 BiVO4 / V4C3 MXene / RGO prepared for Example 2 x Nd y EPR-h + spectrum of the BiVO4 / V4C3 MXene / RGO under dark conditions;

[0026] Figure 6 BiVO4 / V4C3 MXene / RGO prepared for Example 2 x Nd y Phase shift and amplitude-voltage curve of the BiVO4 / V4C3 MXene / RGO;

[0027] Figure 7 BiVO4 / V4C3 MXene / RGO prepared for the present application x Nd y Activity graph of the BiVO4 / V4C3 MXene / RGO in hydrogen reduction of CO2 under dark conditions;

[0028] Figure 8 BiVO4 / V4C3 MXene / RGO prepared for the present application x Nd y UV-visible-near infrared absorption spectrum of the BiVO4 / V4C3 MXene / RGO material;

[0029] Figure 9 Bi prepared for the present application x Nd y VO4 / V4C3 MXene / RGO material in the local amplification of light absorption in 200-800 nm;

[0030] Figure 10 Bi prepared for the present application x Nd y VO4 / V4C3 MXene / RGO photocatalytic reduction of CO2 activity graph under different monochromatic light irradiation;

[0031] Figure 11 Bi prepared for the present application x Nd y VO4 / V4C3 MXene / RGO photo-thermal hydrogenation reduction of CO2 activity graph;

[0032] Figure 12 Bi prepared for the present application x Nd y VO4 / V4C3 MXene / RGO photo-thermal cycle activity graph. DETAILED DESCRIPTION

[0033] The present application is herein described, by way of example only, with reference to certain embodiments thereof. It is readily apparent to a person skilled in the art that variations and modifications of the specific embodiments within the scope of the present application can be made without departing from the spirit of the application. The present application can also be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

[0034] It should be noted that the process equipment or devices not specifically mentioned in the following examples are all conventional equipment or devices in the art.

[0035] It should be noted that the terms "comprising" and "having" and any variations thereof are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or apparatus that includes a list of steps or units not necessarily limited to those clearly identified, but can include other steps or units not clearly identified or inherent to such processes, methods, products or apparatus. In addition, unless otherwise specified, the numbering of the steps of each method is only a convenient tool for identifying the steps of the method, and is not intended to limit the arrangement order of the steps of the method or to limit the scope of the application, and changes or adjustments of the relative relationship, without substantial changes in technical content, are also considered as the scope of the application.

[0036] Example 1:

[0037] Step 1: 2 g of V4AlC3 was slowly added to 40 mL of 49% HF solution to form a mixture, which was stirred uniformly at room temperature, and then placed in a 55°C water bath environment for heating and stirring for 96 h. The obtained mixture was centrifuged, and the precipitate was washed with deionized water until the pH of the supernatant was 7. The precipitate was dried and ground to obtain multilayer V4C3 MXene powder.

[0038] Step 2: 3.45 mmol of graphene oxide was dispersed in 100 mL of deionized water, and ultrasonic stirring was performed for 30 min to form a uniform graphene oxide dispersion; 2.125 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and after stirring uniformly, 20 mL of graphene oxide dispersion was added, and after stirring uniformly, 0.50 mmol of Bi(NO3)3·5H2O and 0.025 mmol of Nd(NO3)3·6H2O were added in sequence and stirred until completely dissolved, and the mixture was uniformly mixed to obtain a mixed system.

[0039] Step 3: The mixed system was subjected to hydrothermal reaction at 200°C for 18 h, and after the reaction temperature decreased to room temperature, the reaction kettle was taken out, and the supernatant was removed. The precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively, and then dried at 65°C for 12 h after centrifugation to obtain a material named Bi1Nd 0.05 VO4 / V4C3 MXene / RGO.

[0040] Photothermal carbon dioxide hydrogenation test:

[0041] An existing self-made glass cup was inverted, and the recess with an upper end diameter of 40 mm could be regarded as a culture dish. 60 mg of Bi1Nd 0.05 VO4 / V4C3 MXene / RGO material of the present embodiment was taken into the culture dish, a small amount of deionized water was added and stirred and dispersed, and then placed in a vacuum oven and dried at 65°C in a vacuum environment. After taking out, the atmospheric pressure photothermal catalytic device was heated to 250°C under the condition of ensuring no gas leakage. The culture dish was placed in the atmospheric pressure photothermal catalytic device, and inert gas was continuously introduced into the device for 10 min (flow rate was 2 mL / min). The inlet and outlet valves were closed, 20 mL of carbon dioxide gas and 60 mL of hydrogen gas were filled into the atmospheric pressure photothermal catalytic device, and the pressure after filling was 0.12 MPa. The reaction was carried out for 3 hours, and a sample (1 mL) was introduced into the gas chromatograph every hour to detect the content of carbon monoxide and methane. Among them, the light source was a 300W xenon lamp, and the auxiliary heating temperature was 250°C.

[0042] Example 2:

[0043] Step 1: 2 g of V4AlC3 was slowly added to 40 mL of HF solution to form a mixture, which was stirred uniformly at room temperature, and then placed in a 55°C water bath environment for heating and stirring for 96 h. The obtained mixture was centrifuged, and the precipitate was washed with deionized water until the pH of the supernatant was 7. The precipitate was dried and ground to obtain multilayer V4C3 MXene powder.

[0044] Step 2: 3.45 mmol of graphene oxide was dispersed in 100 mL of deionized water and ultrasonically stirred for 30 min to form a uniform graphene oxide dispersion; 2.125 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and then 20 mL of the graphene oxide dispersion was added after stirring uniformly. After stirring uniformly, 0.50 mmol of Bi(NO3)3·5H2O and 0.05 mmol of Nd(NO3)3·6H2O were added in sequence and stirred until completely dissolved to obtain a mixture.

[0045] Step 3: The mixture was hydrothermally reacted at 200°C for 18 h. After the reaction temperature decreased to room temperature, the reaction kettle was taken out, and the supernatant was removed. The precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively, and then dried at 65°C for 12 h to obtain a material named Bi1Nd 0.10 VO4 / V4C3 MXene / RGO.

[0046] Dark room temperature carbon dioxide hydrogenation test:

[0047] An existing self-made glass cup was inverted, and the recess with an upper end diameter of 40 mm could be regarded as a culture dish. 60 mg of the Bi1Nd 0.10 VO4 / V4C3 MXene / RGO material of the present embodiment was taken into the culture dish, a small amount of deionized water was added and stirred and dispersed, and then the culture dish was placed in a dark room temperature environment for natural air drying and taken out for standby. The culture dish was placed in the normal pressure photo-thermal catalytic device under the condition of ensuring that the normal pressure photo-thermal catalytic device did not leak gas, and a stainless steel tray was used to shield the light at the top of the normal pressure photo-thermal catalytic device to ensure a dark environment. After the inert gas was continuously introduced into the device for 10 min (the flow rate was 2 mL / min), the inlet and outlet valves were closed, 20 mL of carbon dioxide gas and 60 mL of hydrogen gas were filled into the normal pressure photo-thermal catalytic device, and the pressure after filling was 0.12 MPa. After 3 hours of reaction, the sample (1 mL) was introduced into the gas chromatograph every hour to detect the content of carbon monoxide and methane.

[0048] 250°C dark environment carbon dioxide hydrogenation test:

[0049] An existing self-made glass cup was inverted, and the recess with an upper end diameter of 40 mm could be regarded as a culture dish. 60 mg of the Bi1Nd 0.10VO4 / V4C3 MXene / RGO material in the petri dish, add a small amount of deionized water to stir and disperse, then place it in a vacuum oven, dry at 65°C in a vacuum environment, and then take it out for standby. The normal pressure photo-thermal catalytic device is heated to 250°C, and the petri dish is placed in the normal pressure photo-thermal catalytic device under the condition of ensuring that the normal pressure photo-thermal catalytic device does not leak. A stainless steel tray is used to cover the top of the normal pressure photo-thermal catalytic device to ensure a dark environment. After 10 minutes of continuous inert gas supply (flow rate of 2 mL / min), the inlet and outlet valves are closed, 20 mL of carbon dioxide gas and 60 mL of hydrogen gas are filled into the normal pressure photo-thermal catalytic device, and the pressure after filling is 0.12 MPa. Reaction for 3 hours, sample (1 mL) is injected into the gas chromatograph every hour to detect the content of carbon monoxide and methane. The auxiliary heating temperature is 250°C.

[0050] Photo-thermal carbon dioxide hydrogenation test:

[0051] The existing self-made glass cup is inverted, and the recess with an upper end diameter of 40 mm can be regarded as a petri dish. 60 mg of Bi1Nd 0.10 VO4 / V4C3 MXene / RGO material in the petri dish, add a small amount of deionized water to stir and disperse, then place it in a vacuum oven, dry at 65°C in a vacuum environment, and then take it out for standby. The normal pressure photo-thermal catalytic device is heated to 250°C, and the petri dish is placed in the normal pressure photo-thermal catalytic device under the condition of ensuring that the normal pressure photo-thermal catalytic device does not leak. A stainless steel tray is used to cover the top of the normal pressure photo-thermal catalytic device to ensure a dark environment. After 10 minutes of continuous inert gas supply (flow rate of 2 mL / min), the inlet and outlet valves are closed, 20 mL of carbon dioxide gas and 60 mL of hydrogen gas are filled into the normal pressure photo-thermal catalytic device, and the pressure after filling is 0.12 MPa. Reaction for 3 hours, sample (1 mL) is injected into the gas chromatograph every hour to detect the content of carbon monoxide and methane. The auxiliary heating temperature is 250°C.

[0052] Example 3:

[0053] Step 1: 2 g of V4AlC3 is slowly added to 40 mL of HF solution to form a mixed solution, which is stirred uniformly at room temperature, then heated and stirred in a 55°C water bath environment for 96 h. The obtained mixed system is centrifuged and the precipitate is washed with deionized water until the pH of the supernatant is 7. The obtained precipitate is dried and ground to obtain multi-layer V4C3 MXene powder.

[0054] Step 2: 3.45 mmol of graphene oxide was dispersed into 100 mL of deionized water and ultrasonically stirred for 30 min to form a uniform graphene oxide dispersion; 2.125 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and after being stirred uniformly, 20 mL of the graphene oxide dispersion was added, and after being continuously stirred uniformly, 0.50 mmol of Bi(NO3)3·5H2O and 0.125 mmol of Nd(NO3)3·6H2O were added in sequence and stirred until completely dissolved, and a mixed system was obtained.

[0055] Step 3: The mixed system was hydrothermally reacted at 200℃ for 18h, and after the reaction temperature decreased to room temperature, the reaction kettle was taken out, the supernatant was removed, and the precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively, and after centrifugation, it was dried at 65℃ for 12h to obtain a material named Bi1Nd 0.25 VO4 / V4C3 MXene / RGO.

[0056] Photothermal carbon dioxide hydrogenation test:

[0057] An existing self-made glass cup was inverted, and the recess with an upper end diameter of 40mm could be regarded as a culture dish. 60mg of Bi1Nd 0.25 VO4 / V4C3 MXene / RGO material of the present embodiment was taken into the culture dish, a small amount of deionized water was added and stirred and dispersed, and then it was placed in a vacuum oven and dried at 65℃ in a vacuum environment. After taking out, the atmospheric pressure photothermal catalytic device was warmed to 250℃ under the condition of ensuring that the atmospheric pressure photothermal catalytic device was not leaking. The culture dish was placed in the atmospheric pressure photothermal catalytic device, and inert gas was continuously introduced into the device for 10 min (flow rate was 2 mL / min). The inlet and outlet valves were closed, 20 mL of carbon dioxide gas and 60 mL of hydrogen gas were filled into the atmospheric pressure photothermal catalytic device, and the pressure after filling was 0.12 MPa. The reaction was carried out for 3 hours, and a sample (1 mL) was introduced into the gas chromatograph every hour to detect the content of carbon monoxide and methane. Among them, the light source was a 300W xenon lamp, and the auxiliary heating temperature was 250℃.

[0058] Example 4:

[0059] Step 1: 2g of V4AlC3 was slowly added to 40mL of HF solution to form a mixed solution, and after being stirred uniformly at room temperature, it was placed in a 55℃ water bath environment and heated and stirred for 96h. The obtained mixed system was centrifuged, and the precipitate was washed with deionized water until the pH of the obtained supernatant was 7. The obtained precipitate was dried and ground to obtain multi-layer V4C3 MXene powder.

[0060] Step 2: 3.45 mmol of graphene oxide was dispersed into 100 mL of deionized water and ultrasonically stirred for 30 min to form a uniform graphene oxide dispersion; 2.125 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and after being stirred uniformly, 20 mL of the graphene oxide dispersion was added, and after being continuously stirred uniformly, 0.50 mmol of Bi(NO3)3·5H2O and 0.25 mmol of Nd(NO3)3·6H2O were added in sequence and stirred until completely dissolved, and a mixed system was obtained.

[0061] Step 3: The mixed system was hydrothermally reacted at 200℃ for 18h, and after the reaction temperature decreased to room temperature, the reaction kettle was taken out, the supernatant was removed, and the precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively, and after centrifugation, it was dried at 65℃ for 12h to obtain a material named Bi1Nd 0.50 VO4 / V4C3 MXene / RGO.

[0062] Photothermal carbon dioxide hydrogenation test:

[0063] An existing self-made glass cup was inverted, and the recess with an upper end diameter of 40 mm could be regarded as a culture dish. 60 mg of the Bi1Nd 0.50 VO4 / V4C3 MXene / RGO material of the present embodiment was taken into the culture dish, a small amount of deionized water was added and stirred and dispersed, and then it was placed in a vacuum oven and dried at 65℃ in a vacuum environment. After taking out, the atmospheric pressure photothermal catalytic device was warmed to 250℃ under the condition of ensuring that the atmospheric pressure photothermal catalytic device was not leaking. The culture dish was placed in the atmospheric pressure photothermal catalytic device, and inert gas was continuously introduced into the device for 10 min (flow rate was 2 mL / min). The inlet and outlet valves were closed, 20 mL of carbon dioxide gas and 60 mL of hydrogen gas were filled into the atmospheric pressure photothermal catalytic device, and the pressure after filling was 0.12 MPa. The reaction was carried out for 3 hours, and a sample (1 mL) was introduced into the gas chromatograph every hour to detect the content of carbon monoxide and methane. Among them, the light source was a 300W xenon lamp, and the auxiliary heating temperature was 250℃.

[0064] Example 5:

[0065] Step 1: 2g of V4AlC3 was slowly added to 40 mL of HF solution to form a mixed solution, and after being stirred uniformly at room temperature, it was placed in a 55℃ water bath environment and heated and stirred for 96h. The obtained mixed system was centrifuged, and the precipitate was washed with deionized water until the pH of the obtained supernatant was 7. The obtained precipitate was dried and ground to obtain multi-layer V4C3 MXene powder.

[0066] Step 2: 3.45 mmol of graphene oxide was dispersed into 100 mL of deionized water and ultrasonically stirred for 30 min to form a uniform graphene oxide dispersion; 2.125 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and after being stirred uniformly, 20 mL of the graphene oxide dispersion was added, and after being continuously stirred uniformly, 0.50 mmol of Bi(NO3)3·5H2O and 0.375 mmol of Nd(NO3)3·6H2O were added in sequence and stirred until completely dissolved, and a mixed system was obtained.

[0067] Step 3: The mixed system was hydrothermally reacted at 200℃ for 18h, and after the reaction temperature decreased to room temperature, the reaction kettle was taken out, the supernatant was removed, and the precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively, and after centrifugation, it was dried at 65℃ for 12h to obtain a material named Bi1Nd 0.75 VO4 / V4C3 MXene / RGO.

[0068] Photothermal carbon dioxide hydrogenation test:

[0069] An existing self-made glass cup was inverted, and the recess with an upper end diameter of 40mm could be regarded as a culture dish. 60mg of Bi1Nd 0.75 VO4 / V4C3 MXene / RGO material of the present embodiment was taken into the culture dish, a small amount of deionized water was added and stirred and dispersed, and then it was placed in a vacuum oven and dried at 65℃ in a vacuum environment. After taking out, the atmospheric pressure photothermal catalytic device was warmed to 250℃ under the condition of ensuring that the atmospheric pressure photothermal catalytic device was not leaking. The culture dish was placed in the atmospheric pressure photothermal catalytic device, and inert gas was continuously introduced into the device for 10 min (flow rate was 2 mL / min). The inlet and outlet valves were closed, 20 mL of carbon dioxide gas and 60 mL of hydrogen gas were filled into the atmospheric pressure photothermal catalytic device, and the pressure after filling was 0.12 MPa. The reaction was carried out for 3 hours, and a sample (1 mL) was introduced into the gas chromatograph every hour to detect the content of carbon monoxide and methane. Among them, the light source was a 300W xenon lamp, and the auxiliary heating temperature was 250℃.

[0070] Example 6:

[0071] Step 1: 2g of V4AlC3 was slowly added to 40mL of HF solution to form a mixed solution, and after being stirred uniformly at room temperature, it was placed in a 55℃ water bath environment and heated and stirred for 96h. After centrifugation, the precipitate was washed with deionized water until the pH of the supernatant was 7, and the precipitate was dried. After being ground, a multi-layer V4C3 MXene powder was obtained.

[0072] Step 2: 3.45 mmol of graphene oxide was dispersed into 100 mL of deionized water and stirred ultrasonically for 30 min to form a uniform graphene oxide dispersion; 2.070 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and after being stirred uniformly, 20 mL of the graphene oxide dispersion was added. After being stirred uniformly, 0.50 mmol of Bi(NO3)3·5H2O and 0.05 mmol of Nd(NO3)3·6H2O were added in sequence and stirred until completely dissolved. The mixture was uniformly mixed to obtain a mixed system.

[0073] Step 3: The mixed system was subjected to hydrothermal reaction at 200°C for 18 h. After the reaction temperature decreased to room temperature, the reaction kettle was taken out, and the supernatant was removed after standing. The precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively. After centrifugation, it was dried at 70°C for 10 h to obtain a material named Bi1Nd 0.10 VO4 / V4C3 MXene / RGO.

[0074] The photothermal carbon dioxide hydrogenation test was performed according to the method of Example 1.

[0075] Example 7:

[0076] Step 1: 2 g of V4AlC3 was slowly added to 40 mL of HF solution to form a mixed solution. After being stirred uniformly at room temperature, it was placed in a 55°C water bath environment for heating and stirring for 96 h. After centrifugation, the precipitate was washed with deionized water until the pH of the supernatant was 7. The obtained precipitate was dried and ground to obtain multi-layer V4C3 MXene powder.

[0077] Step 2: 3.45 mmol of graphene oxide was dispersed into 100 mL of deionized water and stirred ultrasonically for 30 min to form a uniform graphene oxide dispersion; 2.070 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and after being stirred uniformly, 20 mL of the graphene oxide dispersion was added. After being stirred uniformly, 0.50 mmol of Bi(NO3)3·5H2O and 0.05 mmol of Nd(NO3)3·6H2O were added in sequence and stirred until completely dissolved. The mixture was uniformly mixed to obtain a mixed system;

[0078] Step 3: The mixed system was subjected to hydrothermal reaction at 200°C for 18 h. After the reaction temperature decreased to room temperature, the reaction kettle was taken out, and the supernatant was removed after standing. The precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively. After centrifugation, it was dried at 70°C for 10 h to obtain a material named Bi1Nd 0.10 VO4 / V4C3 MXene / RGO.

[0079] The photothermal carbon dioxide hydrogenation test was performed according to the method of Example 1.

[0080] Example 8:

[0081] Step 1: 2 g of V4AlC3 was slowly added to 40 mL of HF solution to form a mixed solution, which was stirred uniformly at room temperature, and then placed in a 55°C water bath environment for heating and stirring for 96 h. The obtained mixed system was centrifuged, and the precipitate was washed with deionized water until the pH of the supernatant was 7. The obtained precipitate was dried, ground, and then V4C3 MXene powder was obtained.

[0082] Step 2: 3.45 mmol of graphene oxide was dispersed in 100 mL of deionized water, and ultrasonic stirring was performed for 30 min to form a uniform graphene oxide dispersion solution. 2.125 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and then 20 mL of the graphene oxide dispersion solution was added after stirring uniformly. After continuing to stir uniformly, 0.50 mmol of Bi(NO3)3·5H2O and 0.05 mmol of Nd(NO3)3·6H2O were added in sequence and stirred until completely dissolved. The mixture was uniformly mixed to obtain a mixed system.

[0083] Step 3: The mixed system was hydrothermally reacted at 180°C for 18 h. After the reaction temperature decreased to room temperature, the reaction kettle was taken out, and the supernatant was removed. The precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively. After centrifugation, it was dried at 70°C for 10 h to obtain a material named Bi1Nd 0.10 VO4 / V4C3 MXene / RGO.

[0084] The photothermal carbon dioxide hydrogenation test was performed according to the method of Example 1.

[0085] Example 9:

[0086] Step 1: 2 g of V4AlC3 was slowly added to 40 mL of HF solution to form a mixed solution, which was stirred uniformly at room temperature, and then placed in a 55°C water bath environment for heating and stirring for 96 h. The obtained mixed system was centrifuged, and the precipitate was washed with deionized water until the pH of the supernatant was 7. The obtained precipitate was dried, ground, and then V4C3 MXene powder was obtained.

[0087] Step 2: 3.45 mmol of graphene oxide was dispersed in 100 mL of deionized water, and ultrasonic stirring was performed for 30 min to form a uniform graphene oxide dispersion solution. 2.125 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and then 20 mL of the graphene oxide dispersion solution was added after stirring uniformly. After continuing to stir uniformly, 0.50 mmol of Bi(NO3)3·5H2O and 0.05 mmol of Nd(NO3)3·6H2O were added in sequence and stirred until completely dissolved. The mixture was uniformly mixed to obtain a mixed system.

[0088] Step 3: The mixed system was hydrothermally reacted at 190°C for 18h. After the reaction temperature dropped to room temperature, the reactor was taken out, the supernatant was removed by standing, and the precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively. After centrifugation, it was dried at 70°C for 10h to obtain Bi1Nd 0.10 VO4 / V4C3 MXene / RGO material.

[0089] Photothermal carbon dioxide hydrogenation test was carried out according to the method of Example 1.

[0090] Example 10:

[0091] Step 1: 2g of V4AlC3 was slowly added to 40mL of HF solution to form a mixed solution. After uniform stirring at room temperature, it was heated and stirred in a 55°C water bath environment for 96h. The obtained mixed system was centrifuged and the precipitate was washed with deionized water until the pH of the obtained supernatant was 7. The obtained precipitate was dried and ground to obtain multi-layer V4C3 MXene powder.

[0092] Step 2: 3.45mmoL of graphene oxide was dispersed in 100mL of deionized water and ultrasonically stirred for 30min to form a uniform graphene oxide dispersion; 2.125mmoL of V4C3 MXene powder was dissolved in 40mL of deionized water, and after uniform stirring, 20mL of graphene oxide dispersion was added. After uniform stirring, 0.50mmoL of Bi(NO3)3·5H2O and 0.05mmoL of Nd(NO3)3·6H2O were added in turn and stirred until completely dissolved. The mixture was uniformly mixed to obtain a mixed system;

[0093] Step 3: The mixed system was hydrothermally reacted at 200°C for 16h. After the reaction temperature dropped to room temperature, the reactor was taken out, the supernatant was removed by standing, and the precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively. After centrifugation, it was dried at 70°C for 10h to obtain Bi1Nd 0.10 VO4 / V4C3 MXene / RGO material.

[0094] Photothermal carbon dioxide hydrogenation test was carried out according to the method of Example 1.

[0095] Example 11:

[0096] Step 1: 2g of V4AlC3 was slowly added to 40mL of HF solution to form a mixed solution. After uniform stirring at room temperature, it was heated and stirred in a 55°C water bath environment for 96h. The obtained mixed system was centrifuged and the precipitate was washed with deionized water until the pH of the obtained supernatant was 7. The obtained precipitate was dried and ground to obtain multi-layer V4C3 MXene powder.

[0097] Step 2: 3.45 mmol of graphene oxide was dispersed into 100 mL of deionized water and stirred for 30 min to form a uniform graphene oxide dispersion; 2.125 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and then 20 mL of the graphene oxide dispersion was added. After stirring, 0.50 mmol of Bi(NO3)3·5H2O and 0.05 mmol of Nd(NO3)3·6H2O were added in sequence and stirred until completely dissolved. The mixture was uniformly mixed to obtain a mixed system.

[0098] Step 3: The mixed system was hydrothermally reacted at 200°C for 17 h. After the reaction temperature decreased to room temperature, the reaction kettle was taken out, and the supernatant was removed. The precipitate was washed with deionized water and anhydrous ethanol three times, respectively. After centrifugation, it was dried at 70°C for 10 h to obtain a material named Bi1Nd 0.10 VO4 / V4C3 MXene / RGO.

[0099] The photo-thermal carbon dioxide hydrogenation test was performed according to the method of Example 1.

[0100] Example 12:

[0101] Step 1: 2 g of V4AlC3 was slowly added to 40 mL of HF solution to form a mixed solution. After stirring uniformly at room temperature, it was placed in a 55°C water bath environment for heating and stirring for 96 h. The obtained mixed system was centrifuged and the precipitate was washed with deionized water until the pH of the supernatant was 7. The obtained precipitate was dried and ground to obtain multi-layer V4C3 MXene powder.

[0102] Step 2: 3.45 mmol of graphene oxide was dispersed into 100 mL of deionized water and stirred for 30 min to form a uniform graphene oxide dispersion; 2.125 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and then 20 mL of the graphene oxide dispersion was added. After stirring, 0.50 mmol of Bi(NO3)3·5H2O and 0.05 mmol of Nd(NO3)3·6H2O were added in sequence and stirred until completely dissolved. The mixture was uniformly mixed to obtain a mixed system;

[0103] Step 3: The mixed system was hydrothermally reacted at 200°C for 18 h. After the reaction temperature decreased to room temperature, the reaction kettle was taken out, and the supernatant was removed. The precipitate was washed with deionized water and anhydrous ethanol three times, respectively. After centrifugation, it was dried at 60°C for 10 h to obtain a material named Bi1Nd 0.10 VO4 / V4C3 MXene / RGO.

[0104] The photo-thermal carbon dioxide hydrogenation test was performed according to the method of Example 1.

[0105] Example 13

[0106] Step 1: 2 g of V4AlC3 was slowly added to 40 mL of HF solution to form a mixed solution, which was stirred uniformly at room temperature, and then placed in a 55 °C water bath environment for heating and stirring for 96 h. The obtained mixed system was centrifuged, and the precipitate was washed with deionized water until the pH of the supernatant was 7. The obtained precipitate was dried, ground, and then V4C3 MXene powder was obtained.

[0107] Step 2: 3.45 mmol of graphene oxide was dispersed in 100 mL of deionized water, and ultrasonic stirring was performed for 30 min to form a uniform graphene oxide dispersion solution. 2.125 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and then 20 mL of the graphene oxide dispersion solution was added after stirring uniformly. After continuing to stir uniformly, 0.50 mmol of Bi(NO3)3·5H2O and 0.05 mmol of Nd(NO3)3·6H2O were added in sequence and stirred until all were dissolved. The mixture was uniformly mixed to obtain a mixed system.

[0108] Step 3: The mixed system was subjected to hydrothermal reaction at 200 °C for 18 h. After the reaction temperature decreased to room temperature, the reaction kettle was taken out, and the supernatant was removed. The precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively, and then dried at 65 °C for 10 h after centrifugation to obtain a material named Bi1NdVO4 / V4C3 MXene / RGO. 0.10 VO4 / V4C3 MXene / RGO material.

[0109] The photothermal carbon dioxide hydrogenation test was performed according to the method of Example 1.

[0110] Example 14

[0111] Step 1: 2 g of V4AlC3 was slowly added to 40 mL of HF solution to form a mixed solution, which was stirred uniformly at room temperature, and then placed in a 55 °C water bath environment for heating and stirring for 96 h. The obtained mixed system was centrifuged, and the precipitate was washed with deionized water until the pH of the supernatant was 7. The obtained precipitate was dried, ground, and then V4C3 MXene powder was obtained.

[0112] Step 2: 3.45 mmol of graphene oxide was dispersed in 100 mL of deionized water, and ultrasonic stirring was performed for 30 min to form a uniform graphene oxide dispersion solution. 2.125 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and then 20 mL of the graphene oxide dispersion solution was added after stirring uniformly. After continuing to stir uniformly, 0.50 mmol of Bi(NO3)3·5H2O and 0.05 mmol of Nd(NO3)3·6H2O were added in sequence and stirred until all were dissolved. The mixture was uniformly mixed to obtain a mixed system.

[0113] Step 3: The mixed system was hydrothermally reacted at 200°C for 18h. After the reaction temperature dropped to room temperature, the reactor was taken out, the supernatant was removed after standing, and the precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively. After centrifugation, it was dried at 70°C for 11h to obtain Bi1Nd 0.10 VO4 / V4C3 MXene / RGO material.

[0114] Photothermal carbon dioxide hydrogenation test was carried out according to the method of Example 1.

[0115] Example 15:

[0116] Step 1: 2g V4AlC3 was slowly added to 40mL of HF solution to form a mixed solution. After uniform stirring at room temperature, it was heated and stirred in a 55°C water bath environment for 96h. The obtained mixed system was centrifuged and the precipitate was washed with deionized water until the pH of the obtained supernatant was 7. The obtained precipitate was dried and ground to obtain multi-layer V4C3 MXene powder.

[0117] Step 2: 3.45mmoL of graphene oxide was dispersed in 100mL of deionized water and ultrasonically stirred for 30min to form a uniform graphene oxide dispersion; 2.125mmoL of V4C3 MXene powder was dissolved in 40mL of deionized water, and after uniform stirring, 20mL of graphene oxide dispersion was added. After uniform stirring, 0.50mmoL of Bi(NO3)3·5H2O and 0.05mmoL of Nd(NO3)3·6H2O were added in turn and stirred until completely dissolved. The mixture was uniformly mixed to obtain a mixed system;

[0118] Step 3: The mixed system was hydrothermally reacted at 200°C for 18h. After the reaction temperature dropped to room temperature, the reactor was taken out, the supernatant was removed after standing, and the precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively. After centrifugation, it was dried at 70°C for 11h to obtain Bi1Nd 0.10 VO4 / V4C3 MXene / RGO material.

[0119] Photothermal carbon dioxide hydrogenation test was carried out according to the method of Example 1.

[0120] Comparative Example 1:

[0121] 2g V4AlC3 was slowly added to 40mL of HF solution to form a mixed solution. After uniform stirring at room temperature, it was heated and stirred in a 55°C water bath environment for 96h. The obtained mixed system was centrifuged and the precipitate was washed with deionized water until the pH of the obtained supernatant was 7. The obtained precipitate was dried and ground to obtain multi-layer V4C3 MXene powder.

[0122] Comparative Example 2:

[0123] Step 1: 2 g of V4AlC3 was slowly added to 40 mL of HF solution to form a mixture, which was stirred uniformly at room temperature, and then placed in a 55°C water bath environment for heating and stirring for 96 h. The obtained mixture was centrifuged, and the precipitate was washed with deionized water until the pH of the supernatant was 7. The precipitate was dried and ground to obtain multilayer V4C3 MXene powder.

[0124] Step 2: 3.45 mmol of graphene oxide was dispersed in 100 mL of deionized water and ultrasonically stirred for 30 min to form a uniform graphene oxide dispersion; 2.125 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and then 20 mL of graphene oxide dispersion was added after stirring uniformly. After stirring uniformly, 0.50 mmol of Bi(NO3)3·5H2O was added, and the mixture was stirred until all were dissolved to obtain a mixed system.

[0125] Step 3: The mixed system was hydrothermally reacted at 200°C for 18 h. After the reaction temperature decreased to room temperature, the reaction kettle was taken out, and the supernatant was removed. The precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively, and then dried at 65°C for 12 h to obtain a material named BiVO4 / V4C3 MXene / RGO.

[0126] Dark room temperature carbon dioxide hydrogenation test:

[0127] An existing self-made glass cup was inverted, and the recess with an upper end diameter of 40 mm could be regarded as a culture dish. 60 mg of BiVO4 / V4C3 MXene / RGO material of the present comparative example 2 was taken in the culture dish, a small amount of deionized water was added for stirring and dispersion, and then it was placed in a dark room temperature environment for natural air drying, and then taken out for standby. Under the condition of ensuring that the normal pressure photo-thermal catalytic device did not leak, the culture dish was placed in the normal pressure photo-thermal catalytic device, and the top of the normal pressure photo-thermal catalytic device was shielded with a stainless steel plate to ensure a dark environment. After the device was continuously supplied with inert gas for 10 min (flow rate was 2 mL / min), the inlet and outlet valves were closed, 20 mL of carbon dioxide gas and 60 mL of hydrogen gas were filled into the normal pressure photo-thermal catalytic device, and the pressure after filling was 0.12 MPa. After 3 hours of reaction, the sample (1 mL) was injected into the gas chromatograph every hour to detect the content of carbon monoxide and methane.

[0128] 250°C dark environment carbon dioxide hydrogenation test:

[0129] An existing self-made glass cup was inverted, and the recess with an upper end diameter of 40 mm could be regarded as a culture dish. 60 mg of the BiVO4 / V4C3 MXene / RGO material of the present comparative example 2 was taken into the culture dish, a small amount of deionized water was added for stirring and dispersion, and then the culture dish was placed in a vacuum oven and dried at 65°C in a vacuum environment. The normal pressure photo-thermal catalytic device was heated to 250°C, and the culture dish was placed in the normal pressure photo-thermal catalytic device under the condition that the normal pressure photo-thermal catalytic device was ensured to be airtight. A stainless steel tray was used to shield the light at the top of the normal pressure photo-thermal catalytic device to ensure a dark environment. After the inert gas was continuously introduced into the device for 10 min (the flow rate was 2 mL / min), the inlet and outlet valves were closed, 20 mL of carbon dioxide gas and 60 mL of hydrogen gas were filled into the normal pressure photo-thermal catalytic device, and the pressure after filling was 0.12 MPa. The reaction was carried out for 3 hours, and a sample (1 mL) was introduced into the gas chromatograph every hour to detect the content of carbon monoxide and methane. The auxiliary heating temperature was 250°C.

[0130] Photo-thermal carbon dioxide hydrogenation test:

[0131] An existing self-made glass cup was inverted, and the recess with an upper end diameter of 40 mm could be regarded as a culture dish. 60 mg of the BiVO4 / V4C3 MXene / RGO material of the present comparative example 2 was taken into the culture dish, a small amount of deionized water was added for stirring and dispersion, and then the culture dish was placed in a vacuum oven and dried at 65°C in a vacuum environment. The normal pressure photo-thermal catalytic device was heated to 250°C, and the culture dish was placed in the normal pressure photo-thermal catalytic device under the condition that the normal pressure photo-thermal catalytic device was ensured to be airtight. After the inert gas was continuously introduced into the device for 10 min (the flow rate was 2 mL / min), the inlet and outlet valves were closed, 20 mL of carbon dioxide gas and 60 mL of hydrogen gas were filled into the normal pressure photo-thermal catalytic device, and the pressure after filling was 0.12 MPa. The reaction was carried out for 3 hours, and a sample (1 mL) was introduced into the gas chromatograph every hour to detect the content of carbon monoxide and methane. The auxiliary heating temperature was 250°C.

[0132] Comparative example 3:

[0133] Step 1: 2 g of V4AlC3 was slowly added to 40 mL of HF solution to form a mixed solution. After uniform stirring at room temperature, the mixed solution was heated and stirred in a 55°C water bath environment for 96 h. The obtained mixed system was centrifuged, and the precipitate was washed with deionized water until the pH of the supernatant was 7. The obtained precipitate was dried and ground to obtain a multi-layer V4C3 MXene powder.

[0134] Step 2: 3.45 mmol of graphene oxide was dispersed into 100 mL of deionized water, and ultrasonic stirring was performed for 30 min to form a uniform graphene oxide dispersion; 1.25 mmol of V4C3 MXene powder was dissolved in 40 mL of deionized water, and after being stirred uniformly, 20 mL of graphene oxide dispersion was added, and after being continuously stirred uniformly, 0.25 mmol of Bi(NO3)3·5H2O and 0.05 mmol of Bi(NO3)3·5H2O were added in sequence, and after being stirred until all were dissolved, a mixed system was obtained;

[0135] Step 3: The mixed system was subjected to hydrothermal reaction at 200°C for 18 h, and after the reaction temperature was reduced to room temperature, the reaction kettle was taken out, the supernatant was removed after standing, and the precipitate was washed with deionized water and anhydrous ethanol for 3 times, respectively, and after centrifugation, it was dried at 65°C for 12 h to obtain a material named Bi1Nd 0.10 VO4.

[0136] Dark room temperature carbon dioxide hydrogenation test:

[0137] An existing self-made glass cup was inverted, and the recess with a diameter of 40 mm at the upper end could be regarded as a culture dish. 60 mg of Bi1Nd 0.10 VO4 material of the present comparative example 3 was taken into the culture dish, a small amount of deionized water was added and stirred to disperse, and then it was placed in a dark room temperature environment and naturally air-dried, and then taken out for standby. Under the condition of ensuring that the normal pressure photo-thermal catalytic device does not leak, the culture dish was placed in the normal pressure photo-thermal catalytic device, and a stainless steel tray was used to block the light at the top of the normal pressure photo-thermal catalytic device to ensure the dark environment. After the device was continuously supplied with inert gas for 10 min (flow rate was 2 mL / min), the inlet and outlet valves were closed, 20 mL of carbon dioxide gas and 60 mL of hydrogen gas were filled into the normal pressure photo-thermal catalytic device, and after filling, the pressure was 0.12 MPa. The reaction was carried out for 3 hours, and the sample (1 mL) was introduced into the gas chromatograph every hour to detect the content of carbon monoxide and methane.

[0138] 250°C dark environment carbon dioxide hydrogenation test:

[0139] An existing self-made glass cup was inverted, and the recess with a diameter of 40 mm at the upper end could be regarded as a culture dish. 60 mg of Bi1Nd 0.10The BiVO4 material was added into the petri dish, a small amount of deionized water was added for stirring and dispersion, and then the petri dish was placed in a vacuum oven and dried at 65°C in a vacuum environment. The atmospheric pressure photo-thermal catalytic device was heated to 250°C, and the petri dish was placed in the atmospheric pressure photo-thermal catalytic device under the condition that no gas leakage was ensured. A stainless steel tray was used to shield the light at the top of the atmospheric pressure photo-thermal catalytic device to ensure a dark environment. After 10 minutes of continuous inert gas supply (flow rate: 2 mL / min), the inlet and outlet valves were closed, 20 mL of carbon dioxide gas and 60 mL of hydrogen gas were filled into the atmospheric pressure photo-thermal catalytic device, and the pressure after filling was 0.12 MPa. The reaction was carried out for 3 hours, and a sample (1 mL) was injected into the gas chromatograph every hour to detect the content of carbon monoxide and methane. The auxiliary heating temperature was 250°C.

[0140] Photo-thermal carbon dioxide hydrogenation test:

[0141] A self-made glass cup was inverted, and the recess with an upper end diameter of 40 mm could be regarded as a petri dish. 60 mg of Bi1Nd 0.10 The BiVO4 material was added into the petri dish, a small amount of deionized water was added for stirring and dispersion, and then the petri dish was placed in a vacuum oven and dried at 65°C in a vacuum environment. The atmospheric pressure photo-thermal catalytic device was heated to 250°C, and the petri dish was placed in the atmospheric pressure photo-thermal catalytic device under the condition that no gas leakage was ensured. After 10 minutes of continuous inert gas supply (flow rate: 2 mL / min), the inlet and outlet valves were closed, 20 mL of carbon dioxide gas and 60 mL of hydrogen gas were filled into the atmospheric pressure photo-thermal catalytic device, and the pressure after filling was 0.12 MPa. The reaction was carried out for 3 hours, and a sample (1 mL) was injected into the gas chromatograph every hour to detect the content of carbon monoxide and methane. The auxiliary heating temperature was 250°C.

[0142] The figures appearing in the present application are specifically described as follows.

[0143] Figure 1 BiVO4 / V4C3 MXene / RGO material prepared in the present application x Nd y XRD pattern of the BiVO4 / V4C3 MXene / RGO material. Wherein a and b are V4C3 MXene and BiVO4 / V4C3 MXene / RGO synthesized according to Comparative Examples 1-2, and d, e, f and g are BiVO4 / V4C3 MXene / RGO synthesized according to Examples 2-5, respectively. x Nd yVO4 / V4C3 MXene / RGO piezoelectric catalyst. The diffraction peaks at 2θ = 7.8°, 15.6° correspond to the (002) and (004) crystal planes of V4C3-MXene, respectively. The diffraction peaks at 2θ = 18.9°, 28.9°, 30.5°, 40.2° and 42.4°, 47.2° and 53.2° are attributed to the (011), (112), (004), (121) and (015) crystal planes of monoclinic BiVO4(PDF #83-1700), respectively, and there are no any impurity peaks related to Nd element, which is inferred to be due to the low content or the form of Nd 3+ . 3+ As the content of Nd 0.10 increases, the diffraction peaks corresponding to BiVO4are broadened, which indicates that the grain size of the sample gradually decreases.

[0144] Figure 2 SEM image of Bi1Nd 0.10 VO4 / V4C3 MXene / RGO prepared in Example 2. It can be seen from the figure that the interlayer spacing of the layered V4C3-MXene is larger, and irregular rod-like and sheet-like structures are in situ grown between the layers and on the surface of V4C3 MXene, and a small amount of nano-particles are also attached to the surface of V4C3 MXene.

[0145] Figure 3 SEM image of Bi1Nd 0.10 VO4 prepared in Comparative Example 3. Bi1Nd 0.10 VO4 shows irregular polygonal sheet-like structures formed by mutual stacking of thin sheets, and also contains a large number of agglomerated nano-particle morphologies, which is inferred to be due to the addition of Nd which inhibits the oriented growth of the grain.

[0146] Figure 4 Absorbance curve of Bi1Nd -1 VO4 / V4C3 MXene / RGO prepared in Example 2 for degradation of methylene blue under dark conditions, and the concentration of its own stored electrons is calculated to be 112.9 μmol·g 0.10 .

[0147] Figure 5 EPR-h + spectra of Bi1Nd 0.10 VO4 / V4C3 MXene / RGO prepared in Example 2 under dark conditions. The quantum spin number obtained by EPR spectrum is calculated to be 172.9 μmol g + . -1 It can be seen that the TEMPO-h+ The intensity of the characteristic signal decreases with increasing test time, indicating that the catalyst can release more h+ over time. + This proves that a large number of h are stored on the crystal surface. + .

[0148] Figure 6 Bi1Nd prepared in Example 2 0.10 Phase shift and amplitude-voltage curves of VO4 / V4C3 MXene / RGO. The amplitude-voltage curves exhibit a typical "butterfly ring" pattern, a characteristic of ferroelectric materials. These results demonstrate the piezoelectric properties of the prepared material and provide strong evidence for the intrinsic polarization electric field within its structure. Furthermore, the calculated piezoelectric coefficient value (d...) is... 33 The value is approximately 0.41 nm·V. -1 .

[0149] Figure 7 Bi prepared for this invention x Nd y Activity diagram of CO2 reduction by hydrogenation of VO4 / / V4C3 MXene / RGO in the dark. Where b and h represent BiVO4 / V4C3 MXene / RGO and Bi1Nd synthesized according to comparative examples 2-3, respectively. 0.10 VO4,d is Bi1Nd synthesized according to Example 2. 0.10 VO4 / V4C3 MXene / RGO piezoelectric catalyst. The yields of CO to CO from CO2 produced by the catalytic reduction of CO2 to CO in samples b, d, and h under dark heating were 32.49, 36.17, and 13.47 μmol·g, respectively. cat -1 ·h -1 Among them, sample d under dark heating conditions had a concentration of 5.62 μmol·g. cat -1 ·h -1 Methane formation. Under light- and heat-free conditions, the CO yields of samples b, d, and h were 10.75, 14.52, and 7.69 μmol·g, respectively. cat -1 ·h -1 (The error bar represents the standard deviation of three independent tests). Sample d showed high reduction activity in the dark, which is presumably due to the effect of the RGO piezoelectric effect.

[0150] Figure 8 Bi prepared for this invention x Nd y UV-Vis-NIR absorption spectra of BiVO4 / V4C3 MXene / RGO materials. Where b and h represent the BiVO4 / V4C3 MXene / RGO and Bi1Nd synthesized according to Comparative Examples 2-3, respectively. 0.10VO4, while c, d, e, f, and g are Bi synthesized according to Examples 1-5, respectively. x Nd y VO4 / V4C3MXene / RGO piezoelectric catalyst. Bi x Nd y VO4 / V4C3MXene / RGO exhibits stable and enhanced light absorption across the entire spectrum, as shown in Comparative Example 3 with h(Bi1Nd). 0.10 The VO4 sample exhibits strong absorption primarily in the ultraviolet range, with the absorption edge falling at 526 nm.

[0151] Figure 9 Bi prepared for this invention x Nd y Magnified local images of the light absorption of VO4 / V4C3MXene / RGO materials in the 200–800 nm range. Where b and h represent the BiVO4 / V4C3MXene / RGO and Bi1Nd synthesized according to Comparative Examples 2-3, respectively. 0.10 VO4, while c, d, e, f, and g are Bi synthesized according to Examples 1-5, respectively. x Nd y VO4 / V4C3 MXene / RGO piezoelectric catalyst. The figure shows magnified light absorption patterns of all doped samples in the 200-800 nm range, particularly in the Nd-doped samples. 3+ In the BiVO4 samples, the wavelengths at 593nm, 687nm, and 754nm are generated by Nd2O3. 3+ ground state 4I 9 / 2 Excited to the excited state 4G respectively 5 / 2 4F 9 / 2 and 4F 7 / 2 The presence of absorption peaks at higher energy states is a hallmark of upconversion performance. Compared to the optical absorption diagram of BiVO4 / V4C3 MXene / RGO, the enhanced optical absorption observed in the doped sample can be attributed to Nd... 3+ The enhanced light absorption phenomenon caused by impurity energy levels formed in BiVO4. Sample d exhibits higher light absorption intensity than samples with other doping concentrations; when the Nd concentration is high, Bi... x Nd y The decrease in light absorption intensity of VO4 / V4C3 MXene / RGO may be due to the high Nd concentration leading to Nd... 3+ Cluster formation leads to a self-quenching process, and this concentration quenching process is detrimental to upconversion efficiency.

[0152] Figure 10 Bi prepared for this invention x Nd yPhotocatalytic CO2 reduction yield of VO4 / V4C3 MXene / RGO under different monochromatic light irradiation. Where b represents BiVO4 / V4C3 MXene / RGO synthesized according to Comparative Example 2, and d represents Bi1Nd synthesized according to Example 2. 0.10 VO4 / V4C3 MXene / RGO piezoelectric catalyst. When the catalyst was irradiated with monochromatic light at wavelengths of 740, 850, 940, and 1100 nm, the photocatalytic reduction yields of CO2 in sample d were 2.2, 3.5, 6.4, and 4.1 μmol·g, respectively. cat -1 ·h -1 The reduction yields of sample b at different wavelengths were 4.1, 3.2, 2.4, and 1.7 mol·g, respectively. cat -1 ·h -1 Since Nd's upconversion properties can convert near-infrared light into absorbable visible light, Example 2 can absorb light with wavelengths of 940 and 1100 nm and release it as short-wavelength light of 740 and 850 nm. According to the formula calculation, the proportion of Nd's upconversion effect in the total activity is R = 3.01%, indicating that Nd doping can generate more photogenerated electrons and promote photothermal reduction of CO2 methanation.

[0153] Figure 11 Bi prepared for this invention x Nd y Photothermal hydrogenation activity diagram of BiVO4 / V4C3 MXene / RGO for CO2 reduction. Where b and h represent BiVO4 / V4C3 MXene / RGO and Bi1Nd synthesized according to Comparative Examples 2-3, respectively. 0.10 VO4, while c, d, e, f, and g are Bi synthesized according to Examples 1-5, respectively. x Nd y VO4 / V4C3MXene / RGO piezoelectric catalyst. The yields of CH4 from CO2 produced by photothermal reduction of CO2 for b, c, d, e, f, g, and h were 99.40, 181.68, 229.9, 178.27, 145.49, 130.83, and 21.56 μmol·g, respectively. cat -1 ·h -1 The introduction of Nd increased the CH4 yield, with the optimal sample d yielding 2.3 and 10.6 times that of b and h, respectively.

[0154] Figure 12 Bi1Nd prepared in Example 2 0.10 Photothermal cycling activity diagram of VO4 / V4C3 MXene / RGO. In Example 2, the photothermal reduction CO2 yield remained high after 6 cycles, indicating that this Bi... x Ndy The VO4 / V4C3 MXene / RGO heterojunction photothermal catalyst has good photothermal conversion capacity and cycle stability. Therefore, the conversion rate of the material in the photothermal hydrogenation reduction of carbon dioxide can maintain stability for a long time.

Claims

1. A method for preparing a BNVO / VC MXene / RGO photothermal piezoelectric catalytic material, characterized in that, The photothermal piezocatalytic material is Bi. x Nd y A complex of VO4, V4C3 MXene, and RGO, wherein x:y = 1:(0.5-0.75), is prepared by the following steps: S1, mix the multilayer V4C3 MXene dispersion with the graphene oxide dispersion, add bismuth source and neodymium source, stir to obtain reaction precursor solution; S2, the precursor solution is subjected to hydrothermal reaction, and the resulting product is washed and dried to obtain the BNVO / VC MXene / RGO photothermal piezoelectric catalyst.

2. The preparation method of the BNVO / VC MXene / RGO photothermal piezoelectric catalytic material according to claim 1, characterized in that, In S1, the preparation method of the multilayer V4C3 MXene is as follows: V4AlC3 is etched with HF solution, then washed with water and dried to obtain multilayer V4C3 MXene.

3. The preparation method of the BNVO / VC MXene / RGO photothermal piezoelectric catalytic material according to claim 1, characterized in that, In S1, the molar ratio of multilayer V4C3 MXene to graphene oxide in the reaction precursor solution is (2.5-3.08):

1.

4. The preparation method of the BNVO / VC MXene / RGO photothermal piezoelectric catalytic material according to claim 1, characterized in that, In S1, the bismuth source and the neodymium source are Bi(NO3)3·5H2O and Nd(NO3)3·6H2O, respectively.

5. The preparation method of the BNVO / VC MXene / RGO photothermal piezoelectric catalytic material according to claim 1, characterized in that, In S1, based on the molar ratio, Bi:Nd=1:(0.5-0.75).

6. The method for preparing the BNVO / VC MXene / RGO photothermal piezoelectric catalytic material according to claim 1, characterized in that, In S1, the molar ratio of the bismuth source to the multilayer V4C3 MXene is (0.11-0.24):

1.

7. The preparation method of the BNVO / VC MXene / RGO photothermal piezoelectric catalytic material according to claim 1, characterized in that, In S2, the hydrothermal reaction temperature is 180-200 ℃ and the time is 16-18h.

8. The method for preparing the BNVO / VC MXene / RGO photothermal piezoelectric catalytic material according to claim 1, characterized in that, In S2, the drying temperature is 60-70℃ and the time is 10-12h.

9. The BNVO / VC MXene / RGO photothermal piezoelectric catalytic material obtained by the preparation method according to any one of claims 1-8.

10. The application of the BNVO / VC MXene / RGO photothermal piezoelectric catalytic material according to claim 9 in the catalytic hydrogenation reduction of carbon dioxide to methane.

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