Preparation And Photocatalytic Activity Of Molybdenum Disulfide Matrix Composites

Developing and exploring stable and efficient visible light active photocatalysts to degrade organic pollutants is one of the important strategies to solve environmental problems.In this paper,a molybdenum disulfide（MoS₂）-based composite photocatalyst is designed and prepared to expand the light absorption range and improve the carrier separation efficiency,thereby enhancing the performance of the photocatalyst.The details are as follows:1.The photocatalytis of CC/ZnO/MoS₂ heterojunction structure materials were prepared and the photocatalytic properties were studied.ZnO nanorods were prepared on the carbon cloth by hydrothermal method;then,MoS₂ nanosheets with a thickness of about 20 nm were grown on the surface of ZnO by hydrothermal method.The amount of MoS₂ on the surface of ZnO was adjusted by changing the growth time of MoS₂.The photocatalytic activity of different samples was tested with methylene blue solution as the target pollutant.The photocatalytic performance of the ZnO/MoS₂ heterojunction composite was further tested.The sample with a growth time of 6 h had the highest photocatalytic efficiency,and the degradation rate of 25 mL of 40 ppm methylene blue solution exceeded 90%in 60 min.The narrow band gap of MoS₂ broadens the absorption range of photocatalysts.At the same time,MoS₂ also provides a large number of active sites for photocatalytic reactions.A large number of ZnO/MoS₂interfaces provide a place for carrier separation,and rod-shaped ZnO promotes carrier transport,thereby improving the photocatalytic efficiency of composite materials.2.The photocatalytis of CC/ZnO/Ag/MoS₂ heterojunction structure materials were prepared and the photocatalytic properties were studied.Vacuum deposition method was used to deposit Ag on ZnO nanorods,and then a CC/ZnO/Ag/MoS₂ Z-type heterostructure photocatalyst was constructed.The catalytic performance was optimized by changing the thickness of the deposited Ag.To optimize its catalytic performance,the performance of CC/ZnO/Ag/MoS₂ Z-type heterojunction composites for photocatalytic degradation of methylene blue was tested.It was found that when the thickness of the deposited Ag was 5 nm,the samples had the highest catalytic activity.The degradation rate of 25 mL of 40 ppm methylene blue solution exceeded 98%in 40minutes.Compared with CC/ZnO/MoS₂,the introduction of Ag element makes the composite material constitute a Z-type heterojunction structure,which effectively improves the separation efficiency of electron holes.In addition,the Z-type heterojunction increases the redox potential,making It has a stronger redox capacity and ultimately improves the photocatalytic efficiency of the composite material.3.The photocatalytis of CC/MoS₂/Ag₂S heterojunction structure materials were prepared and the photocatalytic properties were studied.MoS₂ nanosheets with a thickness of about 20 nm were grown on the carbon cloth by a hydrothermal method,and then Ag₂S particles were grown on the MoS₂ nanosheets by an ion layer deposition method.By regulating the ion layer deposition time,the amount of Ag₂S on the MoS₂nanosheets was controlled.The photocatalytic performance of MoS₂/Ag₂S composites for methylene blue degradation was tested.It was found that MoS₂/Ag₂S composites with an ion layer deposition time of 6 min had the highest photocatalytic efficiency,and the degradation rate of 20 mL of 40 ppm methylene blue solution exceeded 90%in 80min.This type of composite material effectively improves the separation efficiency and transfer rate of carriers due to the formation of type II heterojunction,and ultimately improves its catalytic efficiency.