Preparation And Photocatalytic Activity Of New Type Plasmon Photocatalytic Materials

Recently,the problems of environment and energy have become a major challenge all over the world.For the sake of positive reply this kind of challenge, scientific and technological researchers have done a lot of work on attempt and exploration.Due to it enables the conversation from low density of solar energy turn to high density of chemical energy,the photocatalytic technology have become a hot research topic now. TiO2 is an important semiconducting material in photocatalytic technology field,because it is low cost, non-toxic,environmentally friendly and with high chemical stability and thermostability. However, TiO2 is a kind of n-type wide band gap semiconductor(from 3.0 to 3.2 eV),it can be only excited by ultraviolet light,which occupies less than 5% of the solar,the major visible light of solar can not excite it,this limits its practical application under visible light. In order to broaden the response light range of TiO2,enhancing its photocatalytic activity,researchers have done a lot of work on TiO2 modification.Those years surfer plasmon resonance(SPR) enable promote photo-generated electron-hole pairs effective separation, which can improve the utilization of quantum enhance the photocatalytic activity of TiO2 obviously,it have attracted renew attention of photocatalytic researchers,the surfer plasmon resonance on photocatalytic materials have become a hot-spot.The main task of this paper is to use metal surface plasmon resonance effect modify TiO2,endowing it better visible absorption capacity and increasing its photocatalytic activity.Firstly,we prepared plasmon TiO2 nano-particles with chemical deposition-precipitation method combined with photo-reduction method.Studied the photocatalytic activity change regular pattern and mechanism after Ag@AgX combined with TiO2 nano-particles.Optimized the preparation processes and conditions of the metal surface plasmon resonance effect of TiO2 nano-particles by the experimental results.Based on this,we prepared a kind of new type metal surface plasmon resonance effect photocatalytic material:Ag@AgI modified N,F co-doped TiO2 nanotubes named Ag@AgI/N,F-TiO2,researched its photocatalytic performance under visible light.Then,we prepared a new type metal surface plasmon resonance effect porous TiO2 and studier its photocatalytic activity and antibacterial performance.The main contents of this paper:(1) Combined Ag@AgX(X=Cl,Br,I) with TiO2 nano-particles(P25) by chemical deposition-precipitation method and photo-reduction method getting the photocatalytic materials Ag@AgX/TiO2,studied the influence of these conditions of Ag:Ti,photo-reduction time,different silver halide.We found the preparation conditions:Ag:Ti=0.08, the best photo-reduction time was 20min,the best combined silver halide was Agl.The photocatalytic materials prepared had excellent activity,among these samples,the sample of Ag@AgI/TiO2 had the best photocatalytic performance.The results showed that the MO (50ml 20mg/l)degradation rate with the sample of Ag@AgI/TiO2 reached 91.2% under visible light in 90min.(2) Prepared Ag@AgI modified N,F co-doped TiO2 nanotubes with one-pot hydrothermal synthesis method combined with photoreduction method. We found that,firstly,the nanotubes structure had large surface area and strong adsorption ability,which can provide more surface for photocatalytic reactions and absorb more organic pollutant, secondly,while N,F co-doped TiO2 nanotubes,it enable reduce the band gap of TiO2 and broaden its optical response scope,thirdly,after Ag@AgI combined with N,F co-doped TiO2 nanotubes,the band gap getting more narrow, and the optical response scope broadened further.Due to these reasons above,the new type photocatalytic material of Ag@AgI/N,F-TNTs had admirable photocatalytic activity under visible light.The photocatalytic performance order is Ag@AgI/TiO2>Ag@AgBr/TiO2>Ag@AgCl/TiO2. The results showed that the MO (50ml 20mg/l)degradation rate with the sample of Ag@AgI/N,F-TNTs-20 reached 98.2% under visible light in 75min.(3) Based on the results of chapter 3 and chapter 4,using silver-silver sulfide plasma that was seldom researched yet modified TiO2 porous structure composite material prepared by template synthesis method.We studied the process and conditions of synthesis and its photocatalytic activity on MO degradation under visible light and antibacterial performance.The results showed that the sample of Ag@Ag2S/Porous TiO2 had porous structure, its BET specific surface area was 243.9m2/g and the average pore diameter was 2.98nm,the MO (50ml 20mg/l)degradation rate with the sample of Ag@Ag2S/Porous TiO2 reached 98% under visible light in90min,moreover,the catalyst reused for five times, the degradation rate of MO (50ml 20mg/l) remained over 90%.The antibacterial performance test suggested that the sample of Ag@Ag2S/Porous TiO2 also had good antibacterial function.