Cadmium sulfide particles with cage-shaped structure and preparation method and application thereof
阅读说明：本技术 一种笼状结构硫化镉颗粒及其制备方法和应用 (Cadmium sulfide particles with cage-shaped structure and preparation method and application thereof ) 是由 孙丰强 胡椹 梁静妍 李心怡 汪子奕 于 2020-11-27 设计创作，主要内容包括：本发明公开了一种笼状结构硫化镉颗粒及其制备方法和应用。本发明的笼状结构硫化镉颗粒具有由棒状硫化镉聚集形成的笼状结构,其制备方法包括以下步骤：1)将镉源和硫源分散在水中,再加入醇类溶剂,得到反应混合液；2)将步骤1)的反应混合液置于紫外光照射下进行反应,得到笼状结构硫化镉颗粒。本发明的笼状结构硫化镉颗粒的光催化活性高、不易发生团聚,且其制备工艺简单、反应条件温和、原料易得、能耗低、产量高、环境友好,在光催化制氢方面具有很好的应用前景。(The invention discloses a cage-shaped cadmium sulfide particle and a preparation method and application thereof. The cadmium sulfide particles with cage-shaped structures have cage-shaped structures formed by the aggregation of rodlike cadmium sulfides, and the preparation method comprises the following steps: 1) dispersing a cadmium source and a sulfur source in water, and adding an alcohol solvent to obtain a reaction mixed solution; 2) and (2) placing the reaction mixed solution obtained in the step 1) under ultraviolet irradiation for reaction to obtain the cadmium sulfide particles with cage-like structures. The cadmium sulfide particles with cage structures have high photocatalytic activity, are not easy to agglomerate, have simple preparation process, mild reaction conditions, easily available raw materials, low energy consumption, high yield and environmental friendliness, and have good application prospect in the aspect of photocatalytic hydrogen production.)
1. A cage-structured cadmium sulfide particle characterized by: has a cage-like structure formed by the aggregation of rod-shaped cadmium sulfide.
2. Cage-structured cadmium sulfide particles according to claim 1, characterized in that: the particle size of the cage-shaped cadmium sulfide particles is 0.2-1.2 microns.
3. Cage-structured cadmium sulfide particles according to claim 1 or 2, characterized in that: the length of the rod-shaped cadmium sulfide is 40 nm-80 nm.
4. Cage-structured cadmium sulfide particles according to claim 3, characterized in that: the diameter of the holes on the cage walls of the cage-like cadmium sulfide particles is less than 30 nm.
5. The method for producing cage-structured cadmium sulfide particles according to any one of claims 1 to 4, characterized by comprising the steps of:
1) dispersing a cadmium source and a sulfur source in water, and adding an alcohol solvent to obtain a reaction mixed solution;
2) and (2) placing the reaction mixed solution obtained in the step 1) under ultraviolet irradiation for reaction to obtain the cadmium sulfide particles with cage-like structures.
6. The method for producing cage-structured cadmium sulfide particles according to claim 5, characterized in that: the molar ratio of the cadmium source to the sulfur source in the step 1) is 0.25: 1-2: 1.
7. The method for producing cage-structured cadmium sulfide particles according to claim 5 or 6, characterized in that: the cadmium source in the step 1) is at least one of cadmium sulfate, cadmium chloride and cadmium hydroxide; the sulfur source in the step 1) is at least one of sodium sulfide and sodium thiosulfate.
8. The method for producing cage-structured cadmium sulfide particles according to claim 5 or 6, characterized in that: the volume ratio of the water to the alcohol solvent in the step 1) is 1: 1-4: 1.
9. The method for producing cage-structured cadmium sulfide particles according to claim 5 or 6, characterized in that: the alcohol solvent in the step 1) is at least one of methanol, ethanol, ethylene glycol and isopropanol.
10. Use of the cage-structured cadmium sulfide particles according to any one of claims 1 to 4 as a photocatalyst.
Technical Field
The invention relates to the technical field of photocatalysis, in particular to a cage-shaped cadmium sulfide particle and a preparation method and application thereof.
Background
The photocatalysis technology is a green technology with important application prospect in the field of energy and environment, and has the advantages of simple and controllable operation, low energy consumption and the like. The hydrogen production technology by photolysis of water starts from 1972, and is reported by professor Fujishima A and professor Honda K of Tokyo university of Japan for the first time to find TiO2The single crystal electrode can generate hydrogen by photocatalytic water decomposition, thereby revealing the possibility of preparing hydrogen by directly decomposing water by using solar energy and opening up a research road for preparing hydrogen by using solar energy to hydrolyze water.
Cadmium sulfide is a visible light response photocatalyst, has a band gap of 2.42eV, and is one of semiconductor photocatalysts with the most outstanding performance in various sulfides for hydrogen production by photolysis of water. The properties of cadmium sulfide are closely related to the size and shape of crystal grains, and thus, many studies on nano cadmium sulfide have attracted attention. At present, the synthesis method of the nano cadmium sulfide mainly comprises hydrothermal method, template method, microemulsion method and the like, and the problems of complex operation, high energy consumption and the like generally exist, and the prepared nano cadmium sulfide also has the problems of easy agglomeration, poor performance and the like, and is difficult to apply in a large area.
Therefore, there is a need to develop a cadmium sulfide photocatalyst with a novel structure and excellent performance.
Disclosure of Invention
An object of the present invention is to provide cadmium sulfide particles having a cage-like structure.
The second purpose of the present invention is to provide a method for preparing the cage-like cadmium sulfide particle.
The invention also aims to provide application of the cadmium sulfide particles with the cage-shaped structures to photocatalysis.
The technical scheme adopted by the invention is as follows:
a cadmium sulfide particle having a cage structure has a cage structure formed by aggregation of rod-like cadmium sulfide.
Preferably, the particle size of the cage-structured cadmium sulfide particles is 0.2 to 1.2 μm.
Preferably, the length of the rod-shaped cadmium sulfide is 40nm to 80 nm.
Preferably, the diameter of the holes on the cage walls of the cage-like cadmium sulfide particles is less than 30 nm.
The preparation method of the cadmium sulfide particles with the cage-shaped structures comprises the following steps:
1) dispersing a cadmium source and a sulfur source in water, and adding an alcohol solvent to obtain a reaction mixed solution;
2) and (2) placing the reaction mixed solution obtained in the step 1) under ultraviolet irradiation for reaction to obtain the cadmium sulfide particles with cage-like structures.
Preferably, the preparation method of the cadmium sulfide particles with cage-like structures comprises the following steps:
1) dispersing a cadmium source and a sulfur source in water, and adding an alcohol solvent in an ultrasonic process to obtain a reaction mixed solution;
2) and (2) placing the reaction mixed liquid obtained in the step 1) under ultraviolet irradiation for reaction, filtering, washing and drying the filtered solid to obtain the cage-like cadmium sulfide particles.
Preferably, the molar ratio of the cadmium source to the sulfur source in the step 1) is 0.25: 1-2: 1.
More preferably, the molar ratio of the cadmium source to the sulfur source in the step 1) is 1.2:1 to 1.8: 1.
Preferably, the cadmium source in step 1) is at least one of cadmium sulfate, cadmium chloride and cadmium hydroxide.
Further preferably, the cadmium source in step 1) is cadmium sulfate.
Preferably, the sulfur source in step 1) is at least one of sodium sulfide and sodium thiosulfate.
Further preferably, the sulfur source in step 1) is sodium thiosulfate.
Preferably, the volume ratio of the water to the alcohol solvent in the step 1) is 1: 1-4: 1.
Further preferably, the volume ratio of the water to the alcohol solvent in the step 1) is 1.2: 1-1.8: 1.
Preferably, the alcohol solvent in step 1) is at least one of methanol, ethanol, ethylene glycol and isopropanol.
Further preferably, the alcohol solvent in step 1) is ethanol.
Preferably, the ultraviolet light in the step 2) is irradiated by an ultraviolet lamp with the wavelength of 254nm and the power of 16W, the distance between the ultraviolet lamp and the liquid level of the reaction mixed solution is 2.5 cm-6.0 cm, and the radiation intensity is 3mW/cm2～4mW/cm2。
Preferably, the duration of the ultraviolet irradiation in the step 2) is 6-30 h.
Preferably, the washing in step 2) is washing with deionized water.
Preferably, the drying in the step 2) is carried out at 50-80 ℃, and the drying time is 6-24 h.
A photocatalyst comprising the above cage-structured cadmium sulfide particle.
A photocatalyst for photocatalytic hydrogen production comprises the cadmium sulfide particles with the cage-like structure.
The invention has the beneficial effects that: the cadmium sulfide particles with cage structures have high photocatalytic activity, are not easy to agglomerate, have simple preparation process, mild reaction conditions, easily available raw materials, low energy consumption, high yield and environmental friendliness, and have good application prospect in the aspect of photocatalytic hydrogen production.
Drawings
FIG. 1 is an X-ray diffraction pattern of the cage-structured cadmium sulfide particles of example 1.
FIG. 2 is a scanning electron micrograph of the cage-structured cadmium sulfide particles of example 1.
FIG. 3 is a scanning electron micrograph of cage-structured cadmium sulfide particles of example 2.
FIG. 4 is a scanning electron micrograph of the cage-structured cadmium sulfide particles of example 3.
FIG. 5 is a scanning electron micrograph of cage-structured cadmium sulfide particles of example 4.
FIG. 6 is a scanning electron micrograph of cage-structured cadmium sulfide particles of example 5.
Fig. 7 is a scanning electron micrograph of cadmium sulfide particles of comparative example 1.
Fig. 8 is a graph comparing photocatalytic hydrogen production performance of the cage-structured cadmium sulfide particles of example 1 and the cadmium sulfide particles of comparative example 1.
FIG. 9 is a graph showing the comparison of the photocatalytic hydrogen production performance of the cadmium sulfide particles having cage structures of examples 1 to 4.
Detailed Description
The invention will be further explained and illustrated with reference to specific examples.
Example 1:
the preparation method of the cadmium sulfide particles with cage-shaped structures comprises the following steps:
1) dissolving 0.0075mol of cadmium sulfate and 0.005mol of sodium thiosulfate in 30mL of deionized water, dropwise adding 20mL of absolute ethyl alcohol in the ultrasonic process, and continuing to perform ultrasonic dispersion for 15min after the addition is finished to obtain a reaction mixed solution;
2) adding the reaction mixed liquid obtained in the step 1) into a 100mL surface dish, adding a magnetic stirring rotor, controlling the stirring speed at 100r/min, covering a preservative film on the surface dish, transferring to an ultraviolet lamp (power is 16W, wavelength is 254nm), adjusting the height of the liquid level of the reaction mixed liquid from a light source to be 3.4cm, irradiating by the ultraviolet light for 24h, filtering, washing the filtered solid by deionized water for 4 times, and drying in an oven at 60 ℃ for 12h to obtain the cadmium sulfide particles with the cage-shaped structure.
The X-ray diffraction pattern of the cadmium sulfide particles with the cage-shaped structures is shown in figure 1, and the scanning electron micrograph is shown in figure 2.
As can be seen from fig. 1: obvious diffraction peaks appear at 26.5 degrees, 44.0 degrees, 52.2 degrees and 70.6 degrees, respectively correspond to the crystal faces of cadmium sulfide (111), (210), (311) and (331), and are basically free of impurities.
As can be seen from fig. 2: the cage-shaped cadmium sulfide particles are regular in appearance and clear and visible in structure.
Example 2:
the preparation method of the cadmium sulfide particles with cage-shaped structures comprises the following steps:
1) dissolving 0.0075mol of cadmium sulfate and 0.005mol of sodium thiosulfate in 30mL of deionized water, dropwise adding 20mL of methanol in the ultrasonic process, and continuing ultrasonic dispersion for 15min after the addition is finished to obtain a reaction mixed solution;
2) adding the reaction mixed liquid obtained in the step 1) into a 100mL surface dish, adding a magnetic stirring rotor, controlling the stirring speed at 100r/min, covering a preservative film on the surface dish, transferring to an ultraviolet lamp (power of 16W and wavelength of 254nm), adjusting the height of the liquid level of the reaction mixed liquid from a light source to be 3.4cm, irradiating by the ultraviolet light for 24h, filtering, washing the filtered solid by deionized water for 4 times, and drying in an oven at 60 ℃ for 12h to obtain the cadmium sulfide particles with cage structures (the scanning electron microscope picture is shown in figure 3).
Example 3:
the preparation method of the cadmium sulfide particles with cage-shaped structures comprises the following steps:
1) dissolving 0.0075mol of cadmium sulfate and 0.005mol of sodium thiosulfate in 30mL of deionized water, dropwise adding 20mL of ethylene glycol in the ultrasonic process, and continuing ultrasonic dispersion for 15min after the addition is finished to obtain a reaction mixed solution;
2) adding the reaction mixed liquid obtained in the step 1) into a 100mL surface dish, adding a magnetic stirring rotor, controlling the stirring speed at 100r/min, covering a preservative film on the surface dish, transferring to an ultraviolet lamp (power of 16W and wavelength of 254nm), adjusting the height of the liquid level of the reaction mixed liquid from a light source to be 3.4cm, irradiating by the ultraviolet light for 24h, filtering, washing the filtered solid by deionized water for 4 times, and drying in an oven at 60 ℃ for 12h to obtain the cadmium sulfide particles with cage structures (the scanning electron microscope picture is shown in figure 4).
Example 4:
the preparation method of the cadmium sulfide particles with cage-shaped structures comprises the following steps:
1) dissolving 0.0075mol of cadmium sulfate and 0.005mol of sodium thiosulfate in 30mL of deionized water, dropwise adding 20mL of isopropanol in the ultrasonic process, and continuing ultrasonic dispersion for 15min after the addition is finished to obtain a reaction mixed solution;
2) adding the reaction mixed liquid obtained in the step 1) into a 100mL surface dish, adding a magnetic stirring rotor, controlling the stirring speed at 100r/min, covering a preservative film on the surface dish, transferring to an ultraviolet lamp (power 16W, wavelength 254nm), adjusting the height of the liquid level of the reaction mixed liquid from a light source to be 3.4cm, irradiating by the ultraviolet light for 24h, filtering, washing the filtered solid by deionized water for 4 times, and drying in an oven at 60 ℃ for 12h to obtain the cadmium sulfide particles with the cage-shaped structure (the scanning electron microscope picture is shown in figure 5).
Example 5:
the preparation method of the cadmium sulfide particles with cage-shaped structures comprises the following steps:
1) 0.00375mol of cadmium sulfate and 0.0025mol of sodium thiosulfate are dissolved in 30mL of deionized water, 20mL of absolute ethyl alcohol is dripped in the ultrasonic process, and ultrasonic dispersion is continued for 15min after the addition is finished, so that reaction mixed liquid is obtained;
2) adding the reaction mixed liquid obtained in the step 1) into a 100mL surface dish, adding a magnetic stirring rotor, controlling the stirring speed at 100r/min, covering a preservative film on the surface dish, transferring to an ultraviolet lamp (power 16W, wavelength 254nm), adjusting the height of the liquid level of the reaction mixed liquid from a light source to be 3.4cm, irradiating by the ultraviolet light for 24h, filtering, washing the filtered solid by deionized water for 4 times, and drying in an oven at 60 ℃ for 12h to obtain the cadmium sulfide particles with the cage-shaped structure (the scanning electron microscope picture is shown in figure 6).
Example 6:
the preparation method of the cadmium sulfide particles with cage-shaped structures comprises the following steps:
1) dissolving 0.0075mol of cadmium chloride and 0.005mol of sodium thiosulfate in 30mL of deionized water, dropwise adding 20mL of absolute ethyl alcohol in the ultrasonic process, and continuing to perform ultrasonic dispersion for 15min after the addition is finished to obtain a reaction mixed solution;
2) adding the reaction mixed liquid obtained in the step 1) into a 100mL surface dish, adding a magnetic stirring rotor, controlling the stirring speed at 100r/min, covering a preservative film on the surface dish, transferring to an ultraviolet lamp (power is 16W, wavelength is 254nm), adjusting the height of the liquid level of the reaction mixed liquid from a light source to be 3.4cm, irradiating by the ultraviolet light for 24h, filtering, washing the filtered solid by deionized water for 4 times, and drying in an oven at 60 ℃ for 12h to obtain the cadmium sulfide particles with the cage-shaped structure.
Comparative example 1:
a cadmium sulfide particle, the preparation method of which comprises the following steps:
1) dissolving 0.0075mol of cadmium sulfate and 0.005mol of sodium thiosulfate in 50mL of deionized water, and performing ultrasonic dispersion for 15min to obtain a reaction mixed solution;
2) adding the reaction mixed liquid obtained in the step 1) into a 100mL surface dish, adding a magnetic stirring rotor, controlling the stirring speed at 100r/min, covering a preservative film on the surface dish, transferring to an ultraviolet lamp (power of 16W and wavelength of 254nm), adjusting the height of the liquid level of the reaction mixed liquid from a light source to be 3.4cm, irradiating by the ultraviolet light for 24h, filtering, washing the filtered solid by deionized water for 4 times, and drying in an oven at 60 ℃ for 12h to obtain cadmium sulfide particles (a scanning electron microscope picture is shown in figure 7).
As can be seen from FIGS. 2 to 7: after the alcohol solvent is added into the reaction mixed liquid in the step 1), the obtained cadmium sulfide particles have a cage-shaped structure formed by gathering rod-shaped cadmium sulfide with the length of 40 nm-80 nm, the diameter of holes on the walls of the cage is less than 30nm, the alcohol solvent is not added into the reaction mixed liquid in the step 1), and the obtained cadmium sulfide particles are in an irregular agglomeration shape.
Testing the photocatalytic hydrogen production performance:
adding 6.60g (0.525mol) of anhydrous sodium sulfite and 9.00g (0.375mol) of sodium sulfide into a top-illuminated photocatalytic reaction vessel consisting of 500mL of special-shaped heat-resistant glass, adding 100mL of deionized water, adding a magnetic stirrer, stirring until the solid raw material is completely dissolved, adding 40mg of cadmium sulfide photocatalyst sample, ultrasonically dispersing uniformly, connecting the reaction vessel to a photocatalytic activity evaluation system, vacuumizing the reaction vessel through a system glass pipeline to connect the reaction vessel to a system, using a simulated solar light with the power of 7W as a light source, wherein the wavelength range is 400-780 nm, keeping the temperature of the reaction solution at 6 ℃ by an external cooling circulating pump, irradiating the light source to the solution through a top quartz window to generate hydrogen, introducing the hydrogen into a gas chromatograph provided with a thermal conductivity detector through nitrogen gas by the photocatalytic activity evaluation system for detection, and comparing the generated hydrogen with a standard curve (the linear correlation of 99.7%) which is determined in advance, accurate hydrogen quantity is obtained, a sample is taken once per hour in hydrogen measurement, the total sampling time is 4 hours, the hydrogen generation quantity (mu mol/g) is calculated through a standard curve and an ideal gas state equation formula, the comparison graph of the photocatalytic hydrogen production performance of the cadmium sulfide particles with the cage-shaped structure in example 1 and the photocatalytic hydrogen production performance of the cadmium sulfide particles with the cage-shaped structure in comparative example 1 is shown in fig. 8, and the comparison graph of the photocatalytic hydrogen production performance of the cadmium sulfide particles with the cage-shaped structure in examples 1-4 is shown in fig. 9.
As can be seen from fig. 8: the cage-structured cadmium sulfide particles of example 1 are more excellent in photocatalytic hydrogen production performance than the random cadmium sulfide particles of comparative example 1.
As can be seen from fig. 9: compared with other alcohol solvents, the ethanol has better effect, and the obtained cadmium sulfide particles with cage-shaped structures have the best photocatalytic hydrogen production performance.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.