Study On Preparation Of Iron-doped TiO₂ Imprinting Film And Its Photocatalytic Activity

TiO₂ photocatalyst become one of hotspots research in the field of environmental protection due to its stable property,low cost,corrosion resistance and strong oxidation ability which can degradated organic pollutants to carbon dioxide and water.But,there still exist some shortcomings and limits such asbig forbidden band,visible response range is narrow,low light quantum yield and state in use powder form is not easy to recycle and have no selectivity degradation to the pollutants which limited its development and application.To solve the matter,loading TiO₂,modification and molecular imprinting has become the current research and development direction of photocatalysis field.In this paper,The present situation of titanium dioxide photocatalyst research and development at domestic is reviewed.First of all,TiO₂ thin film was loaded on glass by LPD method;Based on the prepared TiO₂ thin film,certain amount of Fe was doped in the film to the reduce the TiO₂ thin film forbidden band width and broadening the photoresponse range to improve the photocatalytic performance;Based on the prepared iron-doped TiO₂ film,The degradation product Nitrophenol was put into the film as a template,which regulated the mineralization process of iron-doped TiO₂ thin film.Then the films were calcinated at 400? to remove the template and form the template regulated iron-doped TiO₂ film photocatalyst.The film photocatalyst have good photocatalytic efficiency and selectivity degradation ability to the template due to the matching of cavity and valence bond interface.Our mainly works are listed below:1.Anatase TiO₂ film was prepared by Liquid Phase Deposition?LPD?method using ammonium hexafluorotitanate as titanium source and boric acid as hydrolytic accelerating agent,The P25 was used as crystal inductor.XRD and SEM characterization showed that with calcination temperature increased,the crystallinity and crystal grains increased too,within 300-500? and the phase compositions of the film were not changed.The film had highest photocatalytic performance for nitrophenol at 400?.Langmuir-Hinshelwood model fits the catalytic kinetics well.2.The work is based on 1,The optimization preparation conditions of film catalyst.The iron-doped TiO₂ film was prepared using Ammonium hexafluorotitanate as titanium source and boric acid as hydrolytic accelerating agent,the P25 was used as crystal inductor and Fe?NO₃?₃·9H₂O as iron source.The iron ratio to Ti is 1.2%,1.4%,1.6%,respectively.XRD and SEM characterization showed that with the increasing of iron doping amount the crystallinity and crystal decreased a little,and the phase compositions aren't changed.The UV-Vis characterization demonstrated that the iron deposition evidently extends the response of photocatalytic materials to visible light and had red shift.When the molar ratio of Fe and Ti is 1.4%,the sample had the highest photocatalytic performance for Nitrophenol.Langmuir-Hinshelwood model fits the catalytic kinetics well.The photocatalytic performance of thin-film catalyst can still keep after use,and had a good recycling performance.3.The nitrophenol was used as template and the work was based on optimized preparation conditions of iron-doped TiO₂ film.The template,which regulated the mineralization process of iron-doped TiO₂ thin film was removed under calcination.The XRD,SEM,BET,FT-IR characterization showed that all the films samples are Anatase TiO₂ and the phase compositions aren't changed when template is added,and there appeared some holes on the surface of the phase,The specific area increased rapidly.When the template adding amount is 0.02 g,The film photocatalysis had highest photocatalytic performance for template?nitrophenol?and degradation process had not changed the Langmuir-Hinshelwood model;By bring in methylene blue,The film photocatalysis degradation of two degradation product were compared.The experimental demonstrated that the prepared imprinted TiO₂ photocatalysis film have selectivity to the template and had better photocatalytic activities to the noon added TiO₂ photocatalysis film.After using for four times,the photocatalytic performance of thin-film catalyst can still keep after use,and had a good recycling performance.