Modification Of Titanium Dioxide Based On Different Morphologies And Its Application In Photocatalysis

With the rapid and in-depth development of photocatalysis technology,photocatalysis has been applied in more fields,and the photocatalytic degradation of organic pollutants is one of the key research areas.With the rapid development of industry and agriculture,a large number of harmful wastewater and sewage have been discharged into rivers or seeped underground.Organic matter is difficult to degrade naturally,leading to increased processing difficulty and cost.Photocatalytic technology is recognized as a promising environmental remediation technology due to its advantages of cleanliness,high efficiency and low energy consumption.Among the various semiconductor-based photocatalysts with good physical and chemical stability,it is the most eye-catching,but its inherent shortcomings are wide band gap,low electron transmission rate,and high recombination rate,which limit the development and practice of technology application.To this end,researchers have adopted various methods to overcome its shortcomings and improve photocatalytic activity.In theory,all photocatalytic reactions are driven by charge carriers.The behavior of charge carriers can be divided into charge generation,separation,migration and surface reaction.The efficiency of charge utilization in each step determines the overall performance of photocatalysis.Since the physical and chemical properties of nanomaterials are closely related to their morphology and size,this paper mainly studies the preparation of different forms of titanium dioxide and its modified composites by simple methods,and the use of simpler methods to prepare semiconductors with novel structures based on titanium dioxide.Materials,and studied the effects of different crystal phases and morphologies on performance.The specific content is as follows:Through different experimental methods,cost-effective modification of titanium dioxide.The research content of this paper mainly includes the following aspects:（1）The core-shell titanium dioxide with nanosheets on the surface was prepared by the self-template method.The template used was the titanium dioxide nanoparticles themselves.The titanium dioxide nanoparticles with nanosheets on the surface and egg-yolk inside were prepared by hydrothermally in an alkaline solution.And through metal deposition,noble metal nanoparticles are loaded on the surface of titanium dioxide.The effect of the increase in specific surface area and different loadings on the photocatalytic activity was explored.The role of core-shell structure in photocatalysis was studied.Through XRD,SEM,TEM,XPS,PL and other characterizations,the role of the core-shell structure in photocatalysis was studied.The results show that the core-shell structure of TiO₂ has higher photocatalytic performance,while the response of noble metal-loaded TiO₂ in the visible light region is greatly enhanced,and the overall performance is qualitatively improved.（2）Using kapok fiber as a template,the hollow tubular structure of kapok fiber was successfully replicated by high-temperature calcination.Because kapok has a hollow rate of up to 90%,it is very suitable for use as a template to prepare metal oxides.Using kapok fiber as a photocatalytic carrier material,a composite of TiO₂ and Ag₃PO₄ was prepared by a simple solution deposition method.The photocatalytic performance of the composite sample of tubular TiO₂ and Ag₃PO₄ prepared by the new method is also discussed.Through XRD,SEM,TEM,XPS,PL,BET and other characterizations,the role of TiO₂ and Ag₃PO₄composite samples in photocatalysis was studied.The results show that Ag₃PO₄/TiO₂photocatalyst is far superior to supported TiO₂.This is because Ag₃PO₄ has the ability to absorb visible light.At the same time,the huge surface area of tubular TiO₂ also makes Ag₃PO₄ nanoparticles have good dispersibility,so the overall catalytic performance is greatly increased.