Study Of Non-Noble Metal Doped Two-Dimensional Materials And Photocatalytic Applications

Due to the advantages of quantum trapping effect,adjustable electronic structure,large comparative area and optimized surface interface,two-dimensional materials are widely used in the energy and environmental fields such as photocatalytic carbon dioxide reduction,photocatalytic water decomposition,photocatalytic nitrogen reduction and photodegradation.However,there are some problems in two-dimensional materials,such as rapid electron-hole recombination rate,low redox ability caused by narrow band structure,and low density of active sites.The research shows that material modification is an effective means to solve the above problems,such as heterogeneous structure regulation,crystal plane engineering,vacancy engineering and other methods can make the properties of two-dimensional materials greatly improved.In this dissertation,two-dimensional materials are taken as the main research object,aiming to explore the modification of non-noble metal elements and construct the photocatalytic system of metal/two-dimensional semiconductor nanocomposite,so as to improve the photocatalytic performance of two-dimensional nanomaterials.The research results of this paper provide some reference for the regulation of 2D material catalytic performance.The main research results are as follows:1.Taking carbon nitride?C₃N₄?as the research object and combining the calculation of the first principle,firstly,we predicted the most stable configuration of non-noble metal element Fe on carbon nitride material,and Fe-C₃N₄ material consistent with the theoretical prediction was synthesized through experiment.Experiments show that effective doping of Fe induces the formation of surface nitrogen defect sites,which greatly increases the concentration of nitrogen vacancies on the surface of the material,thus facilitating nitrogen activation and dissociation.This doping regulates the energy band structure,so as to construct the high-speed light carrier transport channel and broaden the visible light absorption capacity.This material shows the effective improvement of visible light catalytic nitrogen fixation performance.2.Cu was successfully modified on a two-dimensional BiOCl surface by photoreduction method,and the photocatalytic response range of this material was extended to 700 nm.The results showed that Cu/BiOCl exhibited higher carrier separation rate and stronger visible light absorption capacity through effective doping of Cu,and improved visible light catalytic activity.Cu/BiOCl nanocomposites was applied to the degradation experiment of organic pollutant Rhodamine B,which was superior to the catalytic activity of Au,Ag and Pt and other noble metal matrix composite catalytic materials under the same experimental conditions,and showed excellent recyclability...