Preparation method and application of photocatalytic nanomaterial Na2Ni2Ti6O16
The photocatalytic nanomaterial Na2Ni2Ti6O16 prepared by high-temperature solid-phase reaction method solves the problems of low catalyst charge separation efficiency and insufficient redox potential, and achieves the effect of efficient photocatalytic CO2 reduction to produce CO and CH4.
Patent Information
- Application Number
- CN202510859745.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-25
- Publication Date
- 2025-10-17
AI Technical Summary
Existing catalysts have problems with low charge separation efficiency and insufficient redox potential, which limits the improvement of photocatalytic performance.
The photocatalytic nanomaterial Na2Ni2Ti6O16 was prepared by a high-temperature solid-phase reaction method. By optimizing the molar ratio of tetrabutyl titanate, sodium acetate and nickel nitrate and the sintering temperature, a hexagonal sheet-like nanomaterial was obtained.
Efficient photocatalytic CO2 reduction to produce CO and CH4 was achieved, with yields of 70.6 μmol·g-1 and 0.83 μmol·g-1, respectively. After six cycles, the yields stabilized at 11.94 μmol·g-1·h-1 and 0.12 μmol·g-1·h-1.
Smart Images
Figure CN120790157A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of photocatalytic materials, and particularly relates to a preparation method and application of a photocatalytic nanomaterial Na2Ni2Ti6O 16 . BACKGROUND
[0002] Most catalysts have the problem of low charge separation efficiency, and some catalysts are also limited by insufficient redox potential, which seriously restricts the further improvement of the photocatalytic performance. The application successfully prepares a new nanomaterial Na2Ni2Ti6O 16 with excellent photocatalytic performance through a high-temperature solid-phase reaction method. SUMMARY
[0003] The application aims to solve the problems of the prior art and provides a preparation method and application of a photocatalytic nanomaterial Na2Ni2Ti6O 16 , which can be used for photocatalytic CO2 reduction to prepare CO and CH4, and not only expands the titanate-based photocatalytic material system, but also provides an important reference for developing efficient and stable photocatalysts.
[0004] To solve the above technical problems, the application adopts the technical scheme of a preparation method of a photocatalytic nanomaterial Na2Ni2Ti6O 16 .
[0005] S1, tetrabutyl titanate is added dropwise into anhydrous ethanol, and after stirring and uniformly dispersing, sodium acetate and nickel nitrate are sequentially added, and then magnetic stirring and ultrasonic stirring are performed to obtain a mixture;
[0006] S2, the mixture obtained in S1 is dried at a temperature of 80 DEG C, and then naturally cooled to room temperature, and after grinding, a solid powder is obtained;
[0007] S3, the solid powder obtained in S2 is heated at a temperature increasing rate of 3 DEG C / min from room temperature to 900 DEG C, and then sintered at a constant temperature for 2 h, and then naturally cooled to room temperature to obtain the photocatalytic nanomaterial Na2Ni2Ti6O 16 .
[0008] Preferably, the molar ratio of tetrabutyl titanate, sodium acetate and nickel nitrate in S1 is 15:5:3.
[0009] Preferably, the rotating speed of magnetic stirring in S1 is 20 rpm, and the magnetic stirring time is 30 min.
[0010] Preferably, the frequency of the ultrasonic stirring in S1 is 100 Hz, and the time of the ultrasonic stirring is 20 min.
[0011] Preferably, the time of the drying in S2 is 24 h.
[0012] Preferably, the photocatalytic nanomaterial Na2Ni2Ti6O 16 has a hexagonal sheet structure as a whole.
[0013] The application further provides an application of the photocatalytic nanomaterial Na2Ni2Ti6O 16 prepared by the preparation method. 16 The photocatalytic nanomaterial Na2Ni2Ti6O 16 is used for photocatalytic reduction of CO2 to prepare CO and CH4.
[0014] Preferably, the photocatalytic nanomaterial Na2Ni2Ti6O 16 has a CO production of 70.6 μmol·g -1 and a CH4 production of 0.83 μmol·g -1 after photocatalytic reduction of CO2 for 6 h. 16 After the photocatalytic nanomaterial Na2Ni2Ti6O -1 is used for 6 times, the CO yield is 11.94 μmol·g -1 ·h -1 , and the CH4 yield is 0.12 μmol·g -1 ·h .
[0015] Compared with the prior art, the application has the following advantages:
[0016] The photocatalytic nanomaterial Na2Ni2Ti6O 16 prepared by the application can be used for photocatalytic reduction of CO2 to prepare CO and CH4, which not only expands the titanate-based photocatalytic material system, but also provides an important reference for developing high-efficiency and stable photocatalysts.
[0017] The application will be further described in detail below with reference to the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 is an SEM image of the photocatalytic nanomaterial Na2Ni2Ti6O 16 prepared in Example 1 of the application.
[0019] Figure 2 is a crystal structure image (a) and an XRD diffraction image (b) of the photocatalytic nanomaterial Na2Ni2Ti6O 16 prepared in Example 1 of the application. Figure 3photocatalytic nanomaterial Na2Ni2Ti6O 16 Yield graph for catalyzing CO2 reduction to prepare CO.
[0020] Figure 4 photocatalytic nanomaterial Na2Ni2Ti6O 16 Yield graph for catalyzing CO2 reduction to prepare CH4.
[0021] Figure 5 photocatalytic nanomaterial Na2Ni2Ti6O 16 Catalytic CO2 reduction to prepare CO and CH4cycle graph.
[0022] Figure 6 XRD graph of the catalytic material prepared in Example 1 of the present application at different sintering temperatures.
[0023] Figure 7 XRD graph of the catalytic material prepared in Example 1 of the present application at different amounts of substances of raw materials (sodium acetate and nickel nitrate). DETAILED DESCRIPTION
[0024] Example 1
[0025] photocatalytic nanomaterial Na2Ni2Ti6O 16 of the present application, the method is:
[0026] S1, 0.015 mmol of tetrabutyl titanate was added dropwise into 50 mL of anhydrous ethanol, and after stirring and dispersing uniformly, 0.005 mmol of sodium acetate and 0.003 mmol of nickel nitrate were added in turn, and after magnetic stirring at a speed of 20 rpm for 30 min, ultrasonic stirring was carried out at a frequency of 100 Hz for 20 min, to obtain a mixture of substances;
[0027] S2, the mixture of substances obtained in S1 was dried at a temperature of 80℃ for 24 h, and then naturally cooled to room temperature, and after grinding in a mortar, a solid powder substance was obtained;
[0028] S3, the solid powder substance obtained in S2 was transferred to an alumina crucible, and in a tube furnace, the temperature was raised from room temperature to 900℃ at a heating rate of 3℃ / min, and then sintered at a constant temperature for 2 h, and then naturally cooled to room temperature, to obtain photocatalytic nanomaterial Na2Ni2Ti6O 16 .
[0029] The SEM graph of the photocatalytic nanomaterial Na2Ni2Ti6O 16 prepared is as follows: Figure 1As shown, the whole is mainly dominated by nanosheet, the nanosheet is hexagonal flake structure as a whole, about 200 nm long, about 100 nm wide, and about 50 nm thick.
[0030] As shown in Figure 2 , since the standard card of Na2Ni2Ti6O 16 cannot be detected in the current jade database, but Figure 2 the crystal structure of Na2Ni2Ti6O 16 of (a) is consistent with that of Na2Fe2Ti6O 16 , so the XRD diffraction of Na2Fe2Ti6O 16 is currently used. The XRD theoretical simulation results of Na2Ni2Ti6O 16 are shown in Figure 2 (b), and Figure 2 (b) can be seen that the XRD diffraction peaks of Na2Ni2Ti6O 16 are very consistent with those of Na2Fe2Ti6O 16 .
[0031] The photocatalytic nanomaterial Na2Ni2Ti6O 16 prepared in this embodiment is used for photocatalytic reduction of CO2 to prepare CO and CH4.
[0032] Under the condition of not adding a sacrificial reagent, the CO2 photocatalytic reduction performance is evaluated by using a xenon lamp (300W) irradiation system. During the experiment, 15mg of catalyst is uniformly dispersed on a quartz substrate, and then placed in a 100mL closed reactor equipped with a quartz window. Before irradiation, 2mL of deionized water is first injected into the reactor, and high-purity carbon dioxide (99.999%) is purged at a flow rate of 20mL / min for 30min to ensure that the system atmosphere is completely replaced. The photocatalytic reaction is carried out under the irradiation of a 350-780nm full-spectrum xenon lamp for 6h, and the light intensity distribution is enhanced by an internal reflection system during the irradiation. During the reaction, an online gas chromatography system (GC-7920, AuLight, China) is used to quantitatively detect gaseous products every hour, and the quantitative analysis of CO and CH4 is completed by a gas chromatography module equipped with a flame ionization detector (FID).
[0033] As shown in Figure 3 , after 6h of irradiation, the photocatalytic nanomaterial Na2Ni2Ti6O 16 prepared in this embodiment realizes the yield of CO of 70.6μmol·g -1 , while the yield of CO under the condition of no catalyst is 0μmol·g -1 .
[0034] like Figure 4 As shown in the figure, after 6 hours of illumination, the photocatalytic nanomaterial Na2Ni2Ti6O prepared in this example was used as a control with no catalyst added. 16 Achieving a CH4 production of 0.83 μmol·g -1 Without catalyst, the CO production was 0 μmol·g -1 .
[0035] like Figure 5 As shown in Figure 2, after 6 cycles of testing, the yields of CO and CH4 were maintained at 11.94 μmol·g -1 ·h -1 and 0.12 μmol·g -1 ·h -1 , showing excellent catalytic cycle stability.
[0036] This embodiment optimizes the amount of raw materials in step S1 and the sintering temperature in step S3:
[0037] (1) Optimization of sintering temperature in step S1 and step S3
[0038] The preparation method is the same as that of the photocatalytic nanomaterial Na2Ni2Ti6O in Example 1 16 The preparation method is different in that: Figure 6 As shown, the sintering was started at 400℃ according to the stoichiometric ratio (0.015mmol tetrabutyl titanate, 0.005mmol sodium acetate, 0.005mmol nickel nitrate). At 400℃, almost no crystals were formed. At 500℃, NaTiO3 crystals began to form. At 600℃, Na2Ni2Ti6O 16 The formation of phases, but there are NaTiO3 and Na2Ti6O 13 Impurity phase, 700℃~800℃ although the main phase is Na2Ni2Ti6O 16 , but there is a small amount of Na2Ti6O 13 impurity phase, until it increases to 900℃, the main phase of the product is Na2Ni2Ti6O 16 , there is still a small amount of NaTiO3 impurity phase.
[0039] Therefore, the sintering temperature of the preparation method of the present invention is 900°C.
[0040] (2) Optimization of the amount of sodium acetate and nickel nitrate in step S1
[0041] Based on the stoichiometric ratio of (1) and a sintering temperature of 900°C, the amounts of sodium acetate and nickel nitrate were optimized to prepare five different catalytic materials (①-⑤). The raw materials of each catalytic material were adjusted as follows:
[0042] ①900℃+20%Na: 0.015mmol tetrabutyl titanate, 0.006mmol sodium acetate (0.005mmol+0.005mmol×20%, i.e. the amount of sodium acetate increases by 20%), 0.005mmol nickel nitrate.
[0043] ②900℃+40%Na: 0.015mmol tetrabutyl titanate, 0.007mmol sodium acetate (0.005mmol+0.005mmol×40%, i.e. the amount of sodium acetate increased by 40%), 0.005mmol nickel nitrate.
[0044] ③900℃-20% Ni: 0.015mmol tetrabutyl titanate, 0.005mmol, 0.004mmol nickel nitrate (0.005mmol-0.005mmol×20%, i.e., the amount of nickel nitrate is reduced by 20%).
[0045] ④900℃-30% Ni: 0.015mmol tetrabutyl titanate, 0.005mmol, 0.0035mmol nickel nitrate (0.005mmol-0.005mmol×30%, i.e., the amount of nickel nitrate is reduced by 30%).
[0046] ⑤900℃-40% Ni: 0.015mmol tetrabutyl titanate, 0.005mmol, 0.003mmol nickel nitrate (0.005mmol-0.005mmol×40%, i.e. the amount of nickel nitrate is reduced by 30%).
[0047] In order to eliminate the impurity phase, the amount of sodium acetate was increased on the basis of the stoichiometric ratio (i.e. 900℃+20%Na, 900℃+40%Na) and the sintering temperature was 900℃, but there was still Na2Ti6O 13 and NaTi2O3 impurity phase.
[0048] Finally, the amount of nickel nitrate was kept at 0.005 mmol and the amount of nickel nitrate was reduced, such as Figure 7 As shown in Figure 2, when the amount of nickel nitrate decreases by 20% to 30% (900℃-20% Ni, 900℃-30% Ni), the main phase is Na2Ni2Ti6O 16 , but there is still a small amount of NaTi2O3 impurity phase. When the amount of nickel nitrate is reduced by 40% (900℃-40% Ni), pure phase Na2Ni2Ti6O is finally obtained.16 Therefore, the amount of nickel nitrate is 0.003 mmol.
[0049] In summary, the application adopts 0.015 mmol of tetrabutyl titanate, 0.005 mmol of sodium acetate and 0.003 mmol of nickel nitrate to prepare the photocatalytic nanomaterial Na2Ni2Ti6O 16 .
[0050] The above merely describes the preferred embodiments of the application, but does not limit the application. Any simple modification, change and equivalent change of the above embodiments according to the technical essence of the application are still within the protection scope of the technical scheme of the application.
Claims
1. A photocatalytic nanomaterial Na2Ni2Ti6O 16 The preparation method is characterized in that The method is: S1. Tetrabutyl titanate was added dropwise to anhydrous ethanol, and after stirring and dispersing evenly, sodium acetate and nickel nitrate were added in sequence. After magnetic stirring, ultrasonic stirring was performed to obtain a mixture. S2, drying the mixed substance obtained in S1 at a temperature of 80° C., naturally cooling it to room temperature, and grinding it to obtain a solid powder substance; S3, the solid powder obtained in S2 was heated from room temperature to 900 ° C at a heating rate of 3 ° C / min, sintered at a constant temperature for 2 hours, and then naturally cooled to room temperature to obtain the photocatalytic nanomaterial Na2Ni2Ti6O 16 .
2. A photocatalytic nanomaterial Na2Ni2Ti6O according to claim 1 16 The preparation method is characterized in that The molar ratio of tetrabutyl titanate, sodium acetate and nickel nitrate in S1 is 15:5:
3.
3. A photocatalytic nanomaterial Na2Ni2Ti6O according to claim 1 16 The preparation method is characterized in that The rotation speed of the magnetic stirring in S1 was 20 rpm, and the magnetic stirring time was 30 min.
4. A photocatalytic nanomaterial Na2Ni2Ti6O according to claim 1 16 The preparation method is characterized in that The frequency of ultrasonic stirring in S1 is 100 Hz, and the time of ultrasonic stirring is 20 min.
5. A photocatalytic nanomaterial Na2Ni2Ti6O according to claim 1 16 The preparation method is characterized in that The drying time in S2 is 24 h.
6. A photocatalytic nanomaterial Na2Ni2Ti6O prepared by the preparation method according to any one of claims 1 to 5 16 The application is characterized in that The photocatalytic nanomaterial Na2Ni2Ti6O 16 Used for photocatalytic CO2 reduction to produce CO and CH4.
7. The use according to claim 6, characterized in that The photocatalytic nanomaterial Na2Ni2Ti6O 16 After 6 hours of photocatalytic CO2 production, the CO production was 70.6 μmol·g -1 The production of CH4 is 0.83 μmol·g -1 ; The photocatalytic nanomaterial Na2Ni2Ti6O 16 After 6 cycles, the CO yield was 11.94 μmol·g -1 ·h -1 , CH4 yield 0.12 μmol·g -1 ·h -1 .