阅读说明：本技术 一种含有Mn0.5Cd0.5S和Au负载型光催化剂的制备方法 (Containing Mn0.5Cd0.5Preparation method of S and Au supported photocatalyst ) 是由 刘玉民 王兰兰 吕华 武新新 于 2019-09-24 设计创作，主要内容包括：本发明公开了一种含有Mn_(0.5)Cd_(0.5)S和Au负载型光催化剂及其制备方法,属于无机功能材料领域。将MoO_2和Au负载到Mn_(0.5)Cd_(0.5)S上制得负载型光催化剂Mn_(0.5)Cd_(0.5)S/MoO_2/Au,其中：Mn_(0.5)Cd_(0.5)S、MoO_2与Au质量比为1:0.005-0.03:0.01-0.04。本发明中,MoO_2作为助催化剂加入到Mn_(0.5)Cd_(0.5)S中,降低了电子-空穴的复合效率；纳米Au粒子的引入不仅能与Mn_(0.5)Cd_(0.5)S/MoO_2系统形成表面等离子体共振增强光吸收,还有利于Mn_(0.5)Cd_(0.5)S导带电子的迁移,极大地提高了负载型催化剂的光催化活性,产氢速率高达108.154μmol h~(-1)。(The invention discloses a Mn-containing alloy 0.5 Cd 0.5 S and Au supported photocatalyst and a preparation method thereof, belonging to the field of inorganic functional materials. Adding MoO 2 And Au Supported to Mn 0.5 Cd 0.5 Preparing supported photocatalyst Mn on S 0.5 Cd 0.5 S/MoO 2 Au, wherein: mn 0.5 Cd 0.5 S、MoO 2 The mass ratio of the Au to the Au is 1:0.005-0.03: 0.01-0.04. In the present invention, MoO 2 As cocatalyst to Mn 0.5 Cd 0.5 In S, the electron-hole recombination efficiency is reduced; introduction of nano Au particles not only can be combined with Mn 0.5 Cd 0.5 S/MoO 2 The system forms surface plasma resonance to enhance light absorption and is beneficial to Mn 0.5 Cd 0.5 The transfer of S conduction band electrons greatly improves the photocatalytic activity of the supported catalyst, and the hydrogen production rate is up to 108.154 mu mol h ‑1 。)

1. Mn (manganese)_0.5Cd_0.5S/MoO₂The Au-supported photocatalyst is characterized in that: mn in the catalyst_0.5Cd_0.5S、MoO₂The mass ratio of the Au to the Au is 1:0.005-0.03: 0.01-0.04; diffraction peaks exist at 25.0 +/-0.1 degrees, 26.8 +/-0.1 degrees and 28.6 +/-0.1 degrees in XRD; binding energies in XPS exist at 84.0 + -0.1 eV, 87.7 + -0.1 eV, 161.1 + -0.1 eV, 162.3 + -0.1 eV, 226.1 + -0.1 eV, 227.9 + -0.1 eV, 232.4 + -0.1 eV, 404.8 + -0.1 eV, 411.4 + -0.1 eV, 531.6 + -0.1 eV, 641.3 + -0.1 eV, and 652.2 + -0.1 eV.

2. An Mn as set forth in claim 1_0.5Cd_0.5S/MoO₂The preparation method of the Au-supported photocatalyst is characterized by comprising the following steps:

1) dissolving molybdenum trioxide and molybdenum powder in deionized water, adding ammonium chloride, stirring at room temperature, carrying out hydrothermal reaction on the solution at the temperature of 190-210 ℃, and treating to obtain MoO₂And (3) powder.

2) Dissolving L-cystine in deionized water, and adjusting the pH value of the solution to 10-11 by using NaOH to form a mixed solution A; dissolving cadmium acetate dihydrate and manganese acetate dihydrate in deionized water to form a mixed solution B; the MoO obtained in the step 1) is treated₂Powder divisionDispersing in deionized water, and performing ultrasonic treatment to form a C mixed solution; the mixed solution C and the mixed solution B are sequentially dripped into the mixed solution A, and then the solution is subjected to hydrothermal reaction at the temperature of 120-140 ℃ to obtain Mn after treatment_0.5Cd_0.5S/MoO₂And (c) a complex.

3) Mn obtained in the step 2)_0.5Cd_0.5S/MoO₂Dispersing the compound in deionized water, then dropwise adding chloroauric acid solution, performing ultrasonic treatment, adding sodium borohydride solution, and treating to obtain Mn_0.5Cd_0.5S/MoO₂Au supported photocatalyst.

3. The method for preparing a supported photocatalyst according to claim 2, characterized in that: the molar ratio of the molybdenum trioxide to the molybdenum powder in the step 1) is 2: 1.

4. The method for preparing a supported photocatalyst according to claim 2, characterized in that: mn described in step 2)_0.5Cd_0.5S and MoO₂The mass ratio is 1: 0.005-0.03; the molar ratio of L-cystine, cadmium acetate and manganese acetate is 6:1: 1.

5. The method for preparing a supported photocatalyst according to claim 2, characterized in that: mn described in step 3)_0.5Cd_0.5S、MoO₂The mass ratio of the Au to the Au is 1:0.005-0.03: 0.01-0.04; NaBH₄The molar ratio of the Au to the Au is 5: 1.

6. A Mn according to claim 2_0.5Cd_0.5S/MoO₂The preparation method of the Au-supported photocatalyst is characterized by comprising the following steps: in steps 1) and 2), the post-treatment operations are as follows: cooling to room temperature, filtering and washing by water and ethanol, vacuum drying, and grinding.

7. A Mn according to claim 2_0.5Cd_0.5S/MoO₂The preparation method of the Au-supported photocatalyst is characterized by comprising the following steps: in step 3), the operation after treatment is as follows: pumping with water and ethanolFiltering, washing, vacuum drying and grinding.

8. Mn as set forth in claim 1_0.5Cd_0.5S/MoO₂The application of Au supported photocatalyst in photocatalytic hydrogen production.

9. Mn as claimed in claim 8_0.5Cd_0.5S/MoO₂The application of the Au-supported photocatalyst in photocatalytic hydrogen production is characterized in that: the operating conditions were, light source: a 300W xenon lamp; the dosage of the catalyst is as follows: 0.05 g; concentration of the sacrificial agent: 0.1mol/LNa₂S and 0.1mol/LNa₂SO₃。

Technical Field

The invention belongs to the technical field of inorganic materials, and relates to Mn-containing inorganic material_0.5Cd_0.5S and Au supported photocatalyst, in particular to Mn_0.5Cd_0.5S/MoO₂Au supported photocatalyst and a preparation method thereof.

Background

With the continuous development of society, the energy crisis is increasingly serious, and the environmental pollution caused by the continuous exploitation and consumption of fossil fuels is continuously aggravated, so that a novel, reliable and environment-friendly energy source is urgently needed to be developed to solve the current problems. Hydrogen is the most abundant element in nature, the highest content substance in universe, accounting for about 75%, and hydrogen energy is an efficient, clean and sustainable 'carbon-free' energy source. The generation of the photocatalysis technology can utilize solar energy to decompose water to prepare hydrogen, thereby not only solving the energy crisis, but also protecting the environment.

Mn_0.5Cd_0.5The S solid solution has good visible light absorption capacity and a narrower and adjustable forbidden band width, thereby being widely concerned by people and being a potential photocatalytic hydrogen production material. But due to Mn_0.5Cd_0.5The S solid solution is rapidly combined with electrons and holes under the action of light, the quantum efficiency is low, and the photocatalytic activity of the S solid solution is limited.

Therefore, the development of Mn-containing alloy_0.5Cd_0.5The S multi-metal supported photocatalyst further improves the photocatalytic activity and the hydrogen production efficiency, which is very necessary.

Disclosure of Invention

In order to overcome the defects, the invention provides Mn which is simple to operate and easy to realize_0.5Cd_0.5S/MoO₂A preparation method of Au supported photocatalyst. Adding MoO₂And Au Supported to Mn_0.5Cd_0.5S surface, MoO₂As cocatalyst to Mn_0.5Cd_0.5And (S) in the step (A). Mn produced by the method of the present invention_0.5Cd_0.5S/MoO₂The Au supported photocatalyst has the advantages of high quantum efficiency, good photocatalytic hydrogen production activity and the like.

Mn_0.5Cd_0.5S/MoO₂/Au Supported photocatalyst, MoO₂And Au Supported to Mn_0.5Cd_0.5S, the structure is characterized in that: mn_0.5Cd_0.5S、MoO₂The mass ratio of the Au to the Au is 1:0.005-0.03: 0.01-0.04; diffraction peaks exist at 25.0 °, 26.8 ° and 28.6 ° in XRD; binding energies in XPS exist at 84.0eV, 87.7eV, 161.1eV, 162.3eV, 226.1eV, 227.9eV, 232.4eV, 404.8eV, 411.4eV, 531.6eV, 641.3eV, and 652.2 eV. In this specification, all references to XRD and XPS data are allowed to deviate by up to and down to 0.1.

Pure Mn can be obviously observed in an XRD data analysis chart_0.5Cd_0.5The S solid solution has three diffraction peaks at 25.0 degrees, 26.8 degrees and 28.6 degrees, which respectively correspond to a crystal face (100), a crystal face (002) and a crystal face (101), and are matched with the previously reported literature. Mn_0.5Cd_0.5S/MoO₂No MoO was observed in the Au samples₂And Au diffraction peaks, which may be due to MoO₂And a low content of Au or too weak diffraction peak of nano Au particles.

XPS analysis of Mn_0.5Cd_0.5S/MoO₂The element composition of the Au sample can be seen from the graph, and Cd 3d can be seen from the graph_5/2And Cd 3d_3/2Has a binding energy of 404.8eV and 411.4eV, Mn 2p_3/2And Mn 2p_1/2Has a binding energy of 641.3eV and 652.2 eV. Indicating that the sample contains Cd element and Mn element. S2 p in the map_3/2And S2 p_1/2Has a binding energy of 161.1eV and 162.3eV, and Mo 3d, respectively_3/2The binding energies of (A) were 227.9eV and 232.4 eV. The sample was described as containing an S element and an Mo element. The spectrum had a binding energy of 531.6eV, which corresponds to the peak of the O element. In the atlas Au 4f_7/2And Au 4f_5/2The binding energies of (A) and (B) are respectively 84.0eV and 87.7eV, the existence of Au element in the sample is indicated, and the fact that MoO is generated in an XRD pattern is also proved₂And low content of Au or too weak diffraction peak of nano Au particles, resulting in no detection of MoO₂And the cause of Au diffraction peaks. XPS spectrum shows that the three-system composite material contains Cd, Mn, S, Mo, O and Au elements, and further proves that Mn is successfully prepared_0.5Cd_0.5S/MoO₂a/Au composite material.

Mn_0.5Cd_0.5S/MoO₂the/Au composite photocatalyst is characterized by XRD and XPS, and XRD shows that Mn exists_0.5Cd_0.5The diffraction peak of S, other impurity peaks are not found at the same time, which indicates that the prepared sample has high purity; at the same time due to MoO₂And a small amount of Au, MoO₂And Au diffraction peaks were not detected. XPS shows Mn produced_0.5Cd_0.5S/MoO₂the/Au sample contains Cd, Mn, S, Mo, O and Au elements, and further proves that Mn exists in the prepared sample_0.5Cd_0.5S、MoO₂And Au is present.

The preparation method of the composite photocatalyst provided by the invention comprises the following steps:

mn (manganese)_0.5Cd_0.5S/MoO₂The preparation method of the Au-supported photocatalyst is characterized by comprising the following steps:

1) dissolving molybdenum trioxide and molybdenum powder in deionized water, adding ammonium chloride, stirring at room temperature, carrying out hydrothermal reaction on the solution at the temperature of 190-210 ℃, and treating to obtain MoO₂And (3) powder.

Further, in the technical scheme, the molar ratio of the molybdenum trioxide to the molybdenum powder is 2: 1.

2) Dissolving L-cystine in deionized water, and adjusting the pH value of the solution to 10-11 by using NaOH to form a mixed solution A; dissolving cadmium acetate dihydrate and manganese acetate dihydrate in deionized water to form a mixed solution B; the MoO obtained in the step 1) is treated₂Dispersing the powder in deionized water and performing ultrasonic treatment to form a C mixed solution; the mixed solution C and the mixed solution B are sequentially dripped into the mixed solution A, and then the solution is subjected to hydrothermal reaction at the temperature of 120-140 ℃ to obtain Mn after treatment_0.5Cd_0.5S/MoO₂And (c) a complex.

Further, in the above technical means, Mn_0.5Cd_0.5S and MoO₂The mass ratio is 1: 0.005-0.03; the molar ratio of the L-cystine to the cadmium acetate to the manganese acetate is 6:1: 1.

3) Mn obtained in the step 2)_0.5Cd_0.5S/MoO₂The compound is dispersed inAdding chloroauric acid solution dropwise into deionized water, performing ultrasonic treatment, adding sodium borohydride solution, and treating to obtain Mn_0.5Cd_0.5S/MoO₂Au supported photocatalyst.

Further, in the above technical means, Mn_0.5Cd_0.5S、MoO₂The mass ratio of the Au to the Au is 1:0.005-0.03: 0.01-0.04; NaBH₄The molar ratio of the Au to the Au is 5: 1.

Mn prepared according to the above method_0.5Cd_0.5S/MoO₂The Au supported photocatalyst is used for hydrogen production experiment:

the operating conditions are as follows: light source: a 300W xenon lamp; the dosage of the catalyst is as follows: 0.05 g; concentration of the sacrificial agent: 0.1mol/LNa₂S and 0.1mol/LNa₂SO₃. As can be seen from the figure, pure Mn_0.5Cd_0.5The hydrogen production rate of the S catalyst is 19.236 mu mol h^-1And Mn_0.5Cd_0.5S/MoO₂The hydrogen production rate of the Au-supported photocatalyst reaches 108.154 mu mol h^-1And obviously enhanced photocatalytic hydrogen production performance is shown.

To further describe the above Mn_0.5Cd_0.5S/MoO₂The preparation method of the Au-supported photocatalyst comprises the following typical operation steps:

(1)MoO₂the preparation of (1): weighing a certain mass of molybdenum trioxide and molybdenum powder, dissolving the molybdenum trioxide and the molybdenum powder in deionized water at a molar ratio of 2:1, adding ammonium chloride, stirring at room temperature for 2 hours, transferring the solution to a polytetrafluoroethylene kettle, carrying out hydrothermal reaction at the temperature of 190 plus of 210 ℃ for 15 hours, cooling to room temperature after the reaction is finished, carrying out suction filtration and washing on the obtained product through deionized water and absolute ethyl alcohol, and carrying out vacuum drying to obtain MoO₂And (3) powder.

(2)Mn_0.5Cd_0.5S/MoO₂Preparation of composite sample: weighing a certain mass of L-cystine, dissolving in deionized water, and then adjusting the solution with 6M NaOH to make the pH of the solution be 10-11 to form a mixed solution A; weighing a certain mass of cadmium acetate dihydrate and manganese acetate dihydrate, and dissolving in deionized water, wherein the molar ratio of L-cystine, cadmium acetate and manganese acetate is 6:1:1, forming a B mixed solution; MoO obtained in the step (1)₂Dispersing the powder in deionized water, and performing ultrasonic treatment for 0.5 hour to form a C mixed solution; sequentially dripping the mixed solution C and the mixed solution B into the mixed solution A under stirring, transferring the obtained uniformly mixed solution into a polytetrafluoroethylene kettle, keeping the solution at the temperature of 120-140 ℃ for 10 hours, cooling to room temperature after the reaction is finished, performing suction filtration and washing on the obtained product through deionized water and absolute ethyl alcohol, and performing vacuum drying to obtain Mn_0.5Cd_0.5S and MoO₂Mn in a mass ratio of 1:0.005-0.03_0.5Cd_0.5S/MoO₂And (c) a complex.

(3)Mn_0.5Cd_0.5S/MoO₂Preparation of Au complex sample: mn obtained in the step (2)_0.5Cd_0.5S/MoO₂Dispersing the compound in deionized water, then dropwise adding chloroauric acid solution for ultrasound for 30 minutes, adding sodium borohydride aqueous solution after the ultrasound is finished, continuing stirring for 3 hours, after the reaction is completed, performing suction filtration washing, vacuum drying and grinding on the obtained product through deionized water and absolute ethyl alcohol to obtain Mn_0.5Cd_0.5S、MoO₂Mn in a mass ratio of 1:0.005-0.03:0.01-0.04 to Au_0.5Cd_0.5S/MoO₂Au supported photocatalyst.

The invention has the beneficial effects that:

the composite photocatalyst, MoO, prepared by the invention₂As cocatalyst to Mn_0.5Cd_0.5In S, the recombination efficiency of electrons and holes is reduced, more photogenerated electrons are used in the process of photolyzing water to produce hydrogen, and Mn is greatly improved_0.5Cd_0.5The quantum efficiency of S and the hydrogen production efficiency by photolysis of water; the addition of Au nanoparticles can not only enhance light absorption, but also promote electron transfer rate and reduce the recombination of photo-generated electrons and holes, thereby further improving the photocatalytic activity, and Mn_0.5Cd_0.5S/MoO₂The hydrogen production rate of the Au supported photocatalyst reaches 108.154 mu mol h^-1。

Drawings

FIG. 1 shows Mn prepared in example 1 of the present invention_0.5Cd_0.5S、Mn_0.5Cd_0.5S/MoO₂、 Mn_0.5Cd_0.5S/MoO₂XRD pattern of Au;

FIG. 2 shows Mn prepared in example 1 of the present invention_0.5Cd_0.5S/MoO₂XPS spectra of Au supported photocatalyst;

FIG. 3 shows Mn prepared in example 1 of the present invention_0.5Cd_0.5S、Mn_0.5Cd_0.5S/MoO₂、 Mn_0.5Cd_0.5S/MoO₂Hydrogen efficiency diagram of Au photolysis water.

The specific implementation mode is as follows:

the present invention is further described below with reference to examples. It should be noted that the present invention is not limited to the following embodiments.