Preparation And Photocatalytic Properties Of Porous Titanium Dioxide Composites

With the rapid development of modern society,the problems of energy shortage and environmental pollution are becoming more and more serious.The photocatalytic technology converts solar energy into chemical energy,which has the advantages of low energy consumption,mild reaction conditions and no secondary pollution.It has a wide application prospect in the development of new energy and the solution of environmental problems.for the selection of semiconductor photocatalytic materials,titanium dioxide(TiO₂)semiconductor photocatalytic materials have been widely used in the fields of sewage treatment,air purification,antibacterial,self-cleaning materials and hydrogen production from decomposed water with the advantages of non-toxic,inexpensive,good stability and high photocatalytic activity.TiO₂broad band gap,however,can only achieve the absorption of ultraviolet light in sunlight,thus limiting the effective utilization of visible light region.At the same time,due to the high recombination rate of photogenerated electrons and holes on the surface of TiO₂materials during photocatalysis,the process of redox reaction is slowed down and the photocatalytic activity is reduced.This article mainly focuses on the above problems of insufficient light absorption and low charge carrier utilization,based on the structural adjustment of TiO₂nanomaterials and the optimization of photocatalytic performance.By modifying the surface of the TiO₂nanomaterial,the porous material is prepared to improve the utilization rate of light and provide more active sites.In addition,non-metal composite and metal composite solutions are used to realize energy band structure regulation and extend the spectral response of the material to the visible light region,thereby improving the photocatalytic efficiency of the TiO₂-based material.The main research contents are as follows:1.In order to improve the separation and transfer of photo-generated electron-hole pairs,the non-metallic semiconductor g-C₃N₄is introduced and used as a template to grow porous TiO₂to build a semiconductor heterojunction composite structure.The prepared porous g-C₃N₄/TiO₂composite material has extremely strong adsorption capacity and sufficient absorption in the visible light region.Through the photodegradation of the organic dye Rh B,the effective optimization of its photocatalytic performance is studied.2.Combining nanotechnology with bionic technology to realize low-temperature hydrothermal synthesis of TiO₂with butterfly wing structure.The metal Au which has the surface plasmon enhancement effect is deposited on TiO₂to promote the rapid separation of photo-generated carriers,and achieve the absorption of visible light region.The prepared porous Au/TiO₂?PW was used for the photodegradation of organic dye MO to verify the photocatalytic activity of the base TiO₂composite material.In addition,on this basis,combined with photo-thermal conversion and thermal radiation simulation calculation methods to further study the mechanism of thermally assisted enhancement in photocatalytic performance under the synergistic effect of photo-thermal.