Preparation And Properties Of A New Transition Metal Selenide Catalyst

In recent years,in terms of photocatalytic materials,VIA metal compounds have attracted great attention from researchers.Among them,metal sulfides such as SnSe₂,Mo S₂,In₂S₃ and Zn S have the characteristics of narrow band gap and high carrier mobility.Compared with metal sulfides,metal selenides have a narrower band gap and higher carrier mobility,but there are few studies.MoSe₂ is a two-dimensional material with a band gap of only 1.7 e V,which can absorb all ultraviolet and visible light.In addition,due to its two-dimensional structure has a large specific surface area,it is very suitable as a substrate.It can be combined with other transition metal selenides to form a heterojunction,improve the separation rate of photogenerated electrons and holes,thereby improving its photocatalytic performance.This article uses methylene blue as the dye to be degraded,and evaluates the photocatalytic performance of the sample through its degradation effect on methylene blue.And use a series of characterization methods to analyze and research it.The research content of this article is mainly the following three parts:（1）Use the hydrothermal synthesis method,but choose different solvents and reducing agents to prepare MoSe₂.Characterize the obtained samples and test the photocatalytic performance.The results show that the ultra-thin MoSe₂ nanospheres prepared by using ethanol as a solvent are composed of some wrinkled ultra-thin MoSe₂two-dimensional nanosheets,and their thickness is only 2-3 molecular layers,which is much lower than ordinary MoSe₂ nanosheets 6-8 molecular layers.This MoSe₂nanosphere exhibits more excellent photocatalytic performance and photoelectric performance.（2）Load ZnSe nanoparticles on two-dimensional MoSe₂ nanoplates to construct0D/2D heterojunction catalysts.The results show that the photocatalytic performance and photoelectrochemical performance of the heterojunction are 2 times and 2.75 times that of MoSe₂,respectively.Due to the 0D/2D heterostructure and energy band matching between ZnSe and MoSe₂,the separation efficiency of carriers and the photoelectrochemical performance are improved,and the photocatalytic and photoelectrochemical performance of the heterojunction is greatly improved.（3）Load FeSe₂ nanorods on two-dimensional MoSe₂ nanoplates to construct1D/2D heterojunction catalysts.The results show that the composite photocatalyst has a larger ultraviolet light absorption area and specific surface area.And its carrier separation efficiency is also significantly improved.The photocatalytic and photoelectrochemical performances are 3.4 times and 2 times higher than that of MoSe₂nanoplates,respectively.