Modification And Photocatalytic Performance Of Mesoporous TiO₂

In many semiconductor materials, Titanium dioxide is an excellent catalyst．It owns goodchemical stability, inexpensive, corrosion resistance, high catalytic activity. Currently it has avery large potential for development in environmental monitoring, wastewater treatment, andother materials in the field of new energy research. However, the applications inphotocatalysis were limited because of its large bandgap.It only absorb UV and can’t take fulladvantage of visible light. Through doping TiO2may broaden its visible absorption regionand improve its capability in photocatalysis. In recent years, a lot of research work startaround this problem that how to improve the photocatalytic properties of TiO2. The resultsshow that the modification of TiO2can effectively expand its photocatalytic properties in thevisible absorption region.This paper conducted a brief summary and introduction about present research advancesfor TiO2modified.We prepared the new type of TiO2composite materials through conductinganalysis and desigh the experiment innovation and feasibility. Through a series of studiesabout the material analysis and photocatalytic properties proved the efficient promotion of thephotocatalytic properties. In addition, the paper systemically discussed that the crystallinephase and surface morphology of the composites were affected by different modificationmethods.The photocatalytic activities of as prepared composites were studies under UVradiation and visible-light.First we prepared different calcination temperature mesoporous titania by esterhydrolysis method, TiO2-N, TiO2-Fe-N, and prepared TiO2/H3PW12O40by the sol-gel method.Photocatalysts were characterized by XRD, SEM, TEM, IR spectroscopy, nitrogenadsorpion-desorption and other means. Finally, we research the degradation efficiency underUV and visible light irradiation of Rhodamine B.The results show that:we successfully prepared TiO2-N, TiO2-N-Fe，H3PW12O40/TiO2.First, we got the best calcination temperature (400℃) and prepared TiO2-N, TiO2-N-Fe on the basis of the calcination temperature.N, Fe have entered the TiO2lattice or lattice gap, andsignificantly inhibited TiO2anatase phase and rutile phase transtion. Double doped than thesingle doped has larger specific surface area, smaller grain size. Also, doped light catalystshave better degradation of Rodamin B under the visible light irradiation. Because N-dopedTiO2make the band gap narrow,and it improve UV and visible light photocatalytic activity ofTiO2.Fe3+-doped TiO2could improve the electrons and holes separation rate, thus it extend thelife of the carrier and impove the photocatalytic reaction rate.Then we prepared H3PW12O40/TiO2which H3PW12O40anion skeleton structure has notchanged.H3PW12O40uniformly dispersed in the TiO2lattice. Composite material has a largerpore size (5.62nm), high BET specific surface area (180.3m2/g), the loading of H3PW12O40reach19.61%. H3PW12O40-doped increase TiO2specific surface area. Since it increases thecontact area of H3PW12O40/TiO2and Rhodamine B molecules and synergy betweenH3PW12O40and TiO2could effectively curb the photo-generated electron-hole complex. ThusH3PW12O40/TiO2photocatalyst under UV and visible radiation has better photocatalyticdegradation.