The Preparation And Visible-Light Photocatalytic Performance Of Zn_xCu_1-xS Nanostructured Materials

Due to the special optoelectronic properties,semiconductor metal sulfide materials are often selected as research objects in the field of photocatalysis.Copper sulfide is doped by Zn²⁺to form Zn_xCu_1-xS,which improved the stability and the energy band gap of copper sulfide,thus the photocatalytic activity of the material can be significantly enhanced.In this paper,Zn_xCu_1-xS was prepared by microwave,solvothermal and refluxing method,and a series of characterizations were carried out to investigate its photocatalytic properties.The specific contents are as follows:（1）Using copper chloride（CuCl₂·2H₂O）,zinc sulfate（ZnSO₄·7H₂O）and thiourea（NH₂CSNH₂）as raw materials,ethylene glycol as solvent,Zn_xCu_1-xS nanostructured materials were synthesized by microwave method.XRD showed that the product was hexagonal crystal system.SEM showed that different microwave heating time,microwave heating power,microwave heating method,surfactant content,solvent,and zinc doping amount had great influence on the morphology of the product.UV-Vis absorption spectrum showed that the product had the largest absorption intensity in the ultraviolet and visible light regions when x=0.3.The photocatalytic degradation test showed that the degradation rate of methylene blue（MB）could reach 96.36%under the35 W xenon lamp irradiating for 90 min with the Zn_0.3Cu_0.7S as photocatalyst.Cyclic degradation of MB test showed that its photocatalytic stability was good.Kinetic fitting showed that the degradation reaction conformed to the first-order kinetic equation.（2）Using CuCl₂·2H₂O,ZnSO₄·7H₂O and sublimed sulfur（S）as raw materials,ethylene glycol as solvent,Zn_xCu_1-xS superstructure was synthesized by solvothermal method.XRD showed that the product was hexagonal crystal system.SEM showed that different reaction temperature,reaction time,zinc doping amount,and sulfur source had great influence on the morphology of the product.UV-Vis absorption spectrum showed that the product had the strongest absorption capacity for ultraviolet and visible light when x=0.2.The photocatalytic degradation test showed that the degradation rate of MB could reach 93.56%under the 35 W xenon lamp irradiating for 90 min with the Zn_0.2Cu_0.8S as photocatalyst.Cyclic degradation of MB test showed that its photocatalytic stability was good.Using terephthalic acid（TA）as a fluorescent probe and the photocatalytic contral experiment of adding Vc,confirming that the·OH played a crucial role in photocatalysis.Kinetic fitting showed that the degradation reaction conformed to the first-order kinetic equation.（3）Using CuCl₂·2H₂O,zinc chloride（ZnCl₂）and S as raw materials and ethylene glycol as solvent,Zn_xCu_1-xS superstructure composed of nanosheets was synthesized by refluxing method.XRD showed that the product was hexagonal crystal system.SEM showed that different reaction temperature,reaction time,zinc doping amount,copper source and zinc source had great influence on the product morphology.UV-Vis absorption spectrum showed that the product had the strongest absorption capacity for visible light when x=0.3.The photocatalytic degradation test showed that the degradation rate of MB could reach 90.63%under the 35 W xenon lamp irradiating for90 min with the Zn_0.3Cu_0.7S as photocatalyst.Cyclic degradation of MB test showed that its photocatalytic stability was good.Through TA-PL detection technology and the photocatalytic contral experiment of adding Vc,confirming that the·OH was the main active group in the photocatalytic process.Kinetic fitting showed that the degradation reaction conformed to a first-order kinetic equation.