Photocatalytic material, preparation method and application thereof

Abstract

This invention relates to a photocatalytic material, its preparation method, and its application, belonging to the field of photocatalysis technology. This invention combines CdIn2S4 and Ti3C2T... x A ternary high-efficiency photocatalytic material was obtained by effectively constructing multiple components of TiO2 together. The photocatalytic material is Ti3C2T. x @TiO2 / CdIn2S4 ternary S-type heterojunction, wherein Ti3C2T x The mass ratio of TiO2 to CdIn2S4 is 3:1 to 1:1. CdIn2S4, as a ternary metal sulfide (TMS) semiconductor, has a relatively narrow band gap (2.1-2.7 eV). The introduction of CdIn2S4 significantly improves the photocatalytic performance of the material. Experiments have confirmed that the photocatalytic material can effectively utilize visible light to produce hydrogen.

Description

Technical Field

[0001] This invention relates to the field of photocatalysis technology, and in particular to a photocatalytic material, its preparation method, and its application. Background Technology

[0002] The energy crisis and environmental pollution caused by the excessive consumption of fossil fuels pose serious threats to the global economy and ecology. Hydrogen energy, as a clean energy source with high energy density and no pollution, is considered an effective alternative to fossil fuels.

[0003] In recent years, two-dimensional (2D) materials have attracted much attention due to their unique physicochemical properties. 2D materials possess a larger specific surface area, allowing for the exposure of more reactive sites. MXenes are a collective term for emerging two-dimensional transition metal carbides / nitrides / carbonitrides since 2011. Two-dimensional Ti3C2T x (T x =-O, -OH, -F) As one of the most widely studied MXenes, it possesses excellent hydrophilic groups, tunable work function, large specific surface area, abundant surface active sites, and excellent metal-like conductivity, and has been widely used as a cocatalyst in the field of photocatalytic hydrogen production. Ti3C2T x Thermodynamically metastable Ti atoms present on the surface can be oxidized in situ into two-dimensional TiO2 nanosheets without the addition of an additional Ti source. (Ti3C2T) x TiO2's metal-like properties can act as a co-catalyst to form a Schottky junction with semiconductors at the interface, effectively improving separation and migration rates. However, due to TiO2's low activity in the visible light range, its photocatalytic hydrogen production activity is still not ideal. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a photocatalytic material, its preparation method, and its application. The present invention combines CdIn2S4 with Ti3C2T... x @TiO2 components are effectively combined to obtain a ternary photocatalytic material, which has important applications in efficient catalytic hydrogen production.

[0005] To achieve the above objectives, the specific solution adopted by the present invention is as follows: Firstly, a photocatalytic material, specifically 2D / 2D / 2D Ti3C2T. x @TiO2 / CdIn2S4 ternary S-type heterojunction, the Ti3C2T x Ti3C2T in TiO2 / CdIn2S4 ternary S-type heterojunction x The mass ratio of TiO2 to CdIn2S4 is 3:1 to 1:1.

[0006] Secondly, a method for preparing a photocatalytic material includes the following steps: (1) Ti3C2T x @TiO2 nanosheet composite material was ultrasonically dispersed in a mixed solution of ethylene glycol and water; (2) Add CdSO4·8H2O and In(NO3)3·5H2O to the solution obtained in step (1) and stir; (3) Add thioacetamide and sodium citrate to the solution obtained in step (2), and stir ultrasonically to obtain a suspension; (4) The suspension obtained in step (3) is transferred to a PTFE-lined stainless steel autoclave. The autoclave is sealed and heated. The resulting precipitate is centrifuged, washed with ethanol and deionized water, and dried in a vacuum oven to obtain Ti3C2T. x @TiO2 / CdIn2S4 composite material.

[0007] Preferably, the solution obtained in step (1) contains Ti3C2T x The concentration of the TiO2 nanosheet composite material is 1~5 g / L, and the ratio of ethylene glycol to water is 1:10~1:1.

[0008] Preferably, the molar ratio of Cd:In:S in the solution obtained in step (2) is 1:2:4, and the stirring time is 1h-48h. Here, S in this ratio refers to S in thioacetamide.

[0009] Preferably, in step (3), the molar ratio of thioacetamide to sodium citrate is 1.7:1 to 1:1, and the stirring time is 0.5 to 6 hours.

[0010] Preferably, in step (4), the heating temperature is 95~140℃ and the time is 6~24h.

[0011] Thirdly, the application of the aforementioned photocatalytic materials in catalytic hydrogen production.

[0012] Beneficial effects: This invention provides a photocatalytic material, wherein the photocatalytic material is Ti3C2T x The TiO2 / CdIn2S4 ternary S-type heterojunction utilizes CdIn2S4, a ternary metal sulfide (TMS) semiconductor with a relatively narrow band gap (2.1-2.7 eV), which can effectively utilize visible light for hydrogen production. The introduction of CdIn2S4 significantly enhances the material's photocatalytic performance. Attached Figure Description

[0013] Figure 1 These are the XRD patterns of embodiments 1 to 4 of the present invention.

[0014] Figure 2These are SEM images of embodiments 1 to 4 of the present invention.

[0015] Figure 3 This is a comparison chart of hydrogen production in Examples 1 to 4 of the present invention. Detailed Implementation

[0016] This invention involves the effective combination of CdIn2S4 and Ti3C2Tx@TiO2 to obtain a ternary high-efficiency photocatalytic material, wherein the photocatalytic material is Ti3C2Tx@TiO2. x @TiO2 / CdIn2S4 ternary S-type heterojunction, wherein Ti3C2T x The mass ratio of TiO2 to CdIn2S4 is 3:1 to 1:1.

[0017] Ti3C2T x The (001)TiO2(M@T) nanosheet composite material was synthesized according to the reference (Peng C, Yang X, Li Y, Yu H, Wang H, Peng F. Hybrids of two-dimensional Ti3C2 and TiO2 exposing {001}facets toward enhanced photocatalytic activity. ACS Appl Mater Interfaces 2016;8:6051e60.), and the specific preparation method is as follows: 2D / 2D Ti3C2T x MXene@(001) TiO2 nanosheet composites were obtained via a simple hydrothermal method. Typically, a certain amount of monolayer Ti3C2Tx and 0.66 g NaBF4 were added to 60 ml of 1M HCl solution. The mixture was sonicated for 10 min, stirred for 20 min, and then transferred to a 100 ml PTFE-lined stainless steel autoclave. The autoclave was sealed and heated at 160 °C for 7 h. The resulting gray-black precipitate was washed three times with ethanol and DI water, and dried overnight in a vacuum oven at 60 °C to collect Ti3C2Tx. x @ (001) TiO2 nanosheet material.

[0018] The preparation method of the photocatalytic material includes the following steps: (1) Ti3C2T x @(001)TiO2(M@T) nanosheet composite material was ultrasonically dispersed in a mixed solution of ethylene glycol and water; (2) Continue to add CdSO4·8H2O and In(NO3)3·5H2O and stir for a certain period of time; (3) Add thioacetamide (TAA) and sodium citrate and ultrasonically stir for a certain period of time; in this step, due to Ti3C2T x The amount of TiO2 nanosheets added varies, and there is no fixed amount of thioacetamide and sodium citrate; only the molar ratio is controlled to be 1.7:1 to 1:1. Sodium citrate, as a surfactant, allows for the adjustment of product morphology during synthesis by controlling the ratio of sodium citrate to thioacetamide. (4) The final suspension was transferred to a PTFE-lined stainless steel autoclave. The autoclave was sealed and heated for a certain period of time. The resulting precipitate was centrifuged, washed with ethanol and DI water, and dried in a vacuum oven to obtain Ti3C2T. x @TiO2 / CdIn2S4 composite material.

[0019] Preferably, in step (1) Ti3C2T x @(001)The concentration of TiO2(M@T) is 3.3 g / L, and the ratio of ethylene glycol to water is 1:5.

[0020] Preferably, the solution stirring time in step (2) is 24 hours.

[0021] Preferably, the solution in step (3) is ultrasonically stirred for a certain period of time, which is 2 hours.

[0022] Preferably, the heating temperature in step (4) is 140°C and the heating time is 8 hours.

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

[0024] Example 1 200mg of Ti3C2T x @(001)TiO2(M@T) nanosheet composite material was ultrasonically dispersed in a mixed solution containing 50 ml water and 10 ml ethylene glycol. 0.55 mmol CdSO4·8H2O and 1.1 mmol In(NO3)3·5H2O were added and stirred for 10 h, controlling the molar ratio to Cd:In:S = 1:2:4. Subsequently, 1.72 mmol thioacetamide (TAA) and 1.3 mmol sodium citrate were added, stirred for 30 min, and ultrasonicated for 20 min. Finally, the resulting suspension was transferred to a PTFE-lined stainless steel autoclave, which was sealed and heated at 120 °C for 10 h. The resulting precipitate was centrifuged and washed three times with ethanol and DI water, and then dried in a vacuum oven at 60 °C for 12 h to collect Ti3C2T. x @TiO2 / CdIn2S4 composite material.

[0025] Example 2 200mg of Ti3C2T x @(001)TiO2(M@T) nanosheet composite material was ultrasonically dispersed in a mixed solution containing 50 ml water and 10 ml ethylene glycol. 0.43 mmol CdSO4·8H2O and 0.86 mmol In(NO3)3·5H2O were added and stirred for 24 h, controlling the molar ratio to Cd:In:S = 1:2:4. Subsequently, 1.72 mmol thioacetamide (TAA) and 1.032 mmol sodium citrate were added, stirred for 20 min, and ultrasonicated for 10 min. Finally, the resulting suspension was transferred to a PTFE-lined stainless steel autoclave, which was sealed and heated at 140 °C for 8 hours. The resulting precipitate was centrifuged and washed three times with ethanol and DI water, and then dried in a vacuum oven at 60 °C for 12 h to collect Ti3C2T. x @TiO2 / CdIn2S4 composite material.

[0026] Example 3 200mg of Ti3C2T x @(001)TiO2(M@T) nanosheet composite material was ultrasonically dispersed in a mixed solution containing 30 ml water and 30 ml ethylene glycol. 0.6 mmol CdSO4·8H2O and 1.2 mmol In(NO3)3·5H2O were added and stirred for 10 h, controlling the molar ratio to Cd:In:S = 1:2:4. Subsequently, 1.72 mmol thioacetamide (TAA) and 1.6 mmol sodium citrate were added, stirred for 50 min, and ultrasonicated for 10 min. Finally, the resulting suspension was transferred to a PTFE-lined stainless steel autoclave, which was sealed and heated at 110 °C for 15 h. The resulting precipitate was centrifuged and washed three times with ethanol and DI water, and then dried in a vacuum oven at 60 °C for 12 h to collect Ti3C2T. x @TiO2 / CdIn2S4 composite material.

[0027] Example 4 200mg of Ti3C2T x@(001)TiO2(M@T) nanosheet composite material was ultrasonically dispersed in a mixed solution containing 50 ml water and 20 ml ethylene glycol. 0.8 mmol CdSO4·8H2O and 1.6 mmol In(NO3)3·5H2O were added and stirred for 10 h, controlling the molar ratio to Cd:In:S = 1:2:4. Subsequently, 1.72 mmol thioacetamide (TAA) and 1.72 mmol sodium citrate were added, stirred for 30 min, and ultrasonicated for 30 min. Finally, the resulting suspension was transferred to a PTFE-lined stainless steel autoclave, which was sealed and heated at 100 °C for 11 h. The resulting precipitate was centrifuged and washed three times with ethanol and DI water, and then dried in a vacuum oven at 60 °C for 12 h to collect Ti3C2T. x @TiO2 / CdIn2S4 composite material.

[0028] Figure 1 These are the XRD patterns of Examples 1 to 4 of the present invention. As can be seen from the figures, all ternary composite materials have characteristic peaks of TiO2 and CdIn2S4, proving the successful synthesis of the ternary composite materials.

[0029] Figure 2 These are SEM images of Examples 1-4 of this invention. As can be seen from the images, in all examples, each component of the ternary material exhibits a nanosheet structure, proving that 2D / 2D / 2D Ti3C2T x The successful synthesis of the TiO2 / CdIn2S4 ternary composite material was achieved. In Examples 3 and 4, the CdIn2S4 nanosheets completely covered Ti3C2T. x @TiO2 and they reunite.

[0030] Figure 3 This is a comparison chart of hydrogen production in Examples 1 to 4 of the present invention. As can be seen from the chart, all examples have the effect of catalytic hydrogen production, and Example 2 has the highest hydrogen production.

[0031] It should be noted that the above-described embodiments should be understood as illustrative, not as limiting the scope of protection of this invention. The scope of protection of this invention is defined by the claims. For those skilled in the art, some non-essential improvements and adjustments made to this invention without departing from the essence and scope of this invention still fall within the scope of protection of this invention.

Claims

1. A method for preparing a photocatalytic material, characterized in that: Using CdIn2S4 and Ti3C2T x @TiO2 to construct ternary photocatalytic materials, wherein the material is 2D / 2D / 2D Ti3C2T x The TiO2 / CdIn2S4 ternary S-shaped heterojunction, wherein each component of the ternary material exhibits a nanosheet structure; the Ti3C2T x Ti3C2T in TiO2 / CdIn2S4 ternary S-type heterojunction x The mass ratio of TiO2 to CdIn2S4 is 3:1 to 1:1; the preparation method includes the following steps: (1) Ti3C2T x @TiO2 nanosheet composite material was ultrasonically dispersed in a mixed solution of ethylene glycol and water; (2) Add CdSO4·8H2O and In(NO3)3·5H2O to the solution obtained in step (1) and stir; (3) Add thioacetamide and sodium citrate to the solution obtained in step (2), and stir ultrasonically to obtain a suspension; the molar ratio of thioacetamide and sodium citrate is 1.7:1~1:1, and the stirring time is 0.5~6h; (4) The suspension obtained in step (3) is transferred to a PTFE-lined stainless steel autoclave. The autoclave is sealed and heated. The resulting precipitate is centrifuged, washed with ethanol and deionized water, and dried in a vacuum oven to obtain Ti3C2T. x @TiO2 / CdIn2S4 composite material.

2. The preparation method according to claim 1, characterized in that, The solution obtained in step (1) contains Ti3C2T x The concentration of the TiO2 nanosheet composite material is 1~5 g / L, and the ratio of ethylene glycol to water is 1:10~1:

1.

3. The preparation method according to claim 1, characterized in that, The molar ratio of Cd:In:S in the solution obtained in step (2) is 1:2:4, and the stirring time is 1h-48h.

4. The preparation method according to claim 1, characterized in that, In step (4), the heating temperature is 95~140℃ and the time is 6~24h.

5. The application of the photocatalytic material prepared by any one of the preparation methods according to claims 2-4 in catalytic hydrogen production.

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