阅读说明：本技术 一种含有Mn0.5Cd0.5S和Cu2O负载型光催化剂的制备方法 (Containing Mn0.5Cd0.5S and Cu2Preparation method of O-supported photocatalyst ) 是由 吕华 武新新 刘玉民 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Cu_2O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Cu_2O负载到Mn_(0.5)Cd_(0.5)S上制得负载型Mn_(0.5)Cd_(0.5)S光催化剂,其中：Mn_(0.5)Cd_(0.5)S、MoO_2与Cu_2O质量比为1:0.005-0.03:0.005-0.03。本发明中,Cu_2O与Mn_(0.5)Cd_(0.5)S形成p-n异质结,MoO_2作为助催化剂加入到复合光催化及中,降低了电子-空穴的复合效率有利于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170.366μmol h~(-1)。(The invention discloses a Mn-containing alloy 0.5 Cd 0.5 S and Cu 2 An O-supported photocatalyst and a preparation method thereof belong to the field of inorganic functional materials. Adding MoO 2 And Cu 2 O loading to Mn 0.5 Cd 0.5 Preparation of supported Mn on S 0.5 Cd 0.5 An S photocatalyst, wherein: mn 0.5 Cd 0.5 S、MoO 2 And Cu 2 The mass ratio of O is 1:0.005-0.03: 0.005-0.03. In the present invention, Cu 2 O and Mn 0.5 Cd 0.5 S forms a p-n heterojunction, MoO 2 Added into composite photocatalysis and as a cocatalyst, reduces the recombination efficiency of electron-hole 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 170.366 mu mol h ‑1 。)

1. Mn (manganese)_0.5Cd_0.5S/MoO₂/Cu₂An O-supported photocatalyst, characterized in that: mn in the catalyst_0.5Cd_0.5S、MoO₂And Cu₂The mass ratio of O is 1:0.005-0.03: 0.005-0.03; diffraction peaks exist at 25.0 +/-0.1 degrees, 26.8 +/-0.1 degrees and 28.6 +/-0.1 degrees in XRD; XPS shows 161.1. + -. 0.1eV, 162.3. + -. 0.1eV, 226.1. + -. 0.1eV, 227.9. + -. 0.1eV, 232.4. + -. 0.1eV, 404.8. + -. 0.1eV, 411.4. + -. 0.1eV, 531.6. + -. 0.1eV, 641.3. + -. 0.1eV, 652.2. + -. 0.1eV, 932.1. + -. 0.1eV, and 951.7. + -. 0.1eVAt the binding energy.

2. An Mn as set forth in claim 1_0.5Cd_0.5S/MoO₂/Cu₂The preparation method of the O-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 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.

3) Dispersing PVP, copper chloride dihydrate and sodium citrate into deionized water, stirring, and adding Mn obtained in the step 2)_0.5Cd_0.5S/MoO₂Adding the complex into the mixed solution, sequentially dropwise adding sodium hydroxide solution and L-ascorbic acid solution into the mixed solution, aging at 75-85 deg.C, and treating to obtain Mn_0.5Cd_0.5S/MoO₂/Cu₂An O-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 the L-cystine to the cadmium acetate to the 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、MoO₂And Cu₂The mass ratio of O is 1:0.005-0.03: 0.005-0.03; the mass ratio of PVP, copper chloride dihydrate, sodium citrate, sodium hydroxide and L-ascorbic acid is 1:0.05:0.03:0.245: 0.32.

6. A Mn according to claim 2_0.5Cd_0.5S/MoO₂/Cu₂The preparation method of the O-supported photocatalyst is characterized by comprising the following steps: in all steps, the operation after treatment is as follows: cooling to room temperature, filtering and washing by water and ethanol, vacuum drying, and grinding.

7. Mn as set forth in claim 1_0.5Cd_0.5S/MoO₂/Cu₂The application of O-supported photocatalyst in photocatalytic hydrogen production.

8. Mn as claimed in claim 7_0.5Cd_0.5S/MoO₂/Cu₂The application of the O-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 Cu₂O-supported photocatalyst, in particular to Mn_0.5Cd_0.5S/MoO₂/Cu₂An O-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

The invention provides Mn which is simple to operate and easy to realize_0.5Cd_0.5S/MoO₂/Cu₂A preparation method of an O-supported photocatalyst. Adding MoO₂And Cu₂O loading 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/MoO₂/Cu₂The O-supported photocatalyst has the advantages of high quantum efficiency, good photocatalytic hydrogen production activity and the like.

Mn (manganese)_0.5Cd_0.5S/MoO₂/Cu₂O-Supported photocatalyst, MoO₂And Cu₂O loading to Mn_0.5Cd_0.5S, the structure is characterized in that: mn_0.5Cd_0.5S、MoO₂And Cu₂The mass ratio of O is 1:0.005-0.03: 0.005-0.03; diffraction exists at 25.0 degrees, 26.8 degrees and 28.6 degrees in XRDPeak shooting; binding energies exist in XPS at 161.1eV, 162.3eV, 226.1eV, 227.9eV, 232.4eV, 404.8eV, 411.4eV, 531.6eV, 641.3eV, 652.2eV, 932.1eV, and 951.7 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/MoO₂/Cu₂No MoO was observed in the O samples₂And Cu₂O diffraction peaks, which may be due to MoO₂And Cu₂A low O content or too weak diffraction peaks.

XPS analysis of Mn_0.5Cd_0.5S/MoO₂/Cu₂The composition of elements in the O sample can be seen from the map, and Cd 3d_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 binding energy in the spectrum was 531.6eV, which corresponds to the peak of the O element. Cu in spectrum⁺2p_1/2And Cu⁺2p_3/2The binding energy of the molecular sieve is 932.1eV and 951.7eV, the existence of Cu element in the sample is indicated, and the fact that MoO is generated in an XRD pattern is also proved₂And Cu₂A lower O content or too weak diffraction peak resulted in no MoO detection₂And Cu₂Cause of O diffraction peaks. XPS spectrum shows that the three-system composite material contains Cd, Mn, S, Mo, O and Cu elements, and further proves that Mn is successfully prepared_0.5Cd_0.5S/MoO₂/Cu₂And (3) an O composite material.

Mn_0.5Cd_0.5S/MoO₂/Cu₂The O composite photocatalyst is characterized by XRD and XPS, and XRD shows that Mn exists_0.5Cd_0.5Of SDiffraction peaks, and 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 Cu₂Small amount of supported O, MoO₂And Cu₂The O diffraction peak was not detected. XPS shows Mn produced_0.5Cd_0.5S/MoO₂/Cu₂The O sample contains Cd, Mn, S, Mo, O and Cu elements, and further proves that Mn exists in the prepared sample_0.5Cd_0.5S、MoO₂And Cu₂O 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) Dispersing PVP, copper chloride dihydrate and sodium citrate into deionized water, stirring, and adding Mn obtained in the step 2)_0.5Cd_0.5S/MoO₂Adding the complex into the mixed solution, and sequentially dropwise adding sodium hydroxide solution and L-ascorbic acid solution into the mixed solutionAging the mixed solution at 75-85 deg.C to obtain Mn_0.5Cd_0.5S/MoO₂/Cu₂An O-supported photocatalyst. Wherein PVP is polyvinylpyrrolidone in short.

Further, in the above technical means, Mn_0.5Cd_0.5S、MoO₂And Cu₂The mass ratio of O is 1:0.005-0.03: 0.005-0.03; the mass ratio of PVP, copper chloride dihydrate, sodium citrate, sodium hydroxide and L-ascorbic acid is 1:0.05:0.03:0.245: 0.32.

Mn prepared according to the above method_0.5Cd_0.5S/MoO₂/Cu₂The O-supported photocatalyst is used for hydrogen production experiment:

the operating conditions are as follows: light source: a 300W xenon lamp; amount of catalyst: 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/MoO₂/Cu₂The hydrogen production rate of the O-supported photocatalyst reaches 170.366 mu molh^-1And obviously enhanced photocatalytic hydrogen production performance is shown.

To further describe the above Mn_0.5Cd_0.5S/MoO₂/Cu₂The preparation method of the O-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 material at 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, adjusting the solution with 6M NaOH to pH 10-11 to obtain mixture AA solution; 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, so as to form a mixed solution B; 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/MoO₂/Cu₂Preparation of O composite sample: dispersing PVP, copper chloride dihydrate and sodium citrate in deionized water, stirring for 30 minutes, and adding Mn obtained in the step 2)_0.5Cd_0.5S/MoO₂Adding the compound into the mixed solution, then sequentially dropwise adding a sodium hydroxide solution and an L-ascorbic acid solution into the mixed solution, aging at 75-85 ℃ for 3 hours, after the reaction is completely cooled to room temperature, carrying out suction filtration washing, vacuum drying and grinding on the obtained product through deionized water and absolute ethyl alcohol, and treating to obtain Mn_0.5Cd_0.5S、 MoO₂And Cu₂Mn with O mass ratio of 1:0.005-0.03:0.005-0.03_0.5Cd_0.5S/MoO₂/Cu₂An O-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; cu₂O and Mn_0.5Cd_0.5S forms a p-n heterojunction, which not only can enhance light absorption, but also can promote electron transfer rate and reduce the recombination of photo-generated electrons and holesThereby further improving the photocatalytic activity, Mn_0.5Cd_0.5S/MoO₂/Cu₂The hydrogen production rate of the O-supported photocatalyst reaches 170.366 mu molh^-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/MoO₂/Cu₂An XRD pattern of O;

FIG. 2 shows Mn prepared in example 1 of the present invention_0.5Cd_0.5S/MoO₂/Cu₂XPS spectra of O-supported photocatalysts;

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/MoO₂/Cu₂And (3) generating a hydrogen efficiency diagram by photolysis of O.

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.