Preparation Of Nanocomposite Interfacial Photocatalyst And Its Photocatalytic Degradation Of Phenol Pollutant

Titanium dioxide (TiO2) is widely used in photodegradation of organic pollutants due totheir many significant advantages such as non-toxic, high activity, stability and lowconsumption. When TiO2particles is illuminated by incident light exceeding its band gapenergy, photoproduction electron (e-) from conduction band will reduce O2into peroxidehydroxyl radicals (·HO2-) and left photoproduction holes (h+) will oxide OH-and H2O intohydroxyl radicals (·OH) on valence band. These active radicals can oxide numbers ofrefractory pollutants almost without selectivity. But TiO2only can respond to ultraviolet light,and the e-and h+composite extremely easily on the surface, causing the low photocatalyticefficiency. Meanwhile, present researchers attempt to improve the photocatalytic efficiencymainly by broadening optical response range, reducing the e-and h+recombination rate andthe synthesis of diversified and functional nanomaterials. However, in this paper, a novel,simple and can effective method was adopted to improve the efficiency ofphotocatalytic---constructing nanocomposite interface.Anatase TiO2and leaf-like BiVO4were synthesized via a hydrothermal method, whichwere two kinds of photocatalyst carriers responded to the ultraviolet and visible light,respectively. And rutile Ti0.7W0.3O2and spherical WC acted as co-catalysts were alsosynthesized though a sol-gel method and hydrothermal method, repectively. The three kindsof WC/TiO2, Ti0.7W0.3O2/TiO2and Ti0.7W0.3O2/BiVO4nanocomposite interface wereconstructed, and the crystal structure and surface morphology were invested via XRD andSEM technologies.First of all, based on the advantageous performance of WC such as strong acid resistance,good electrical conductivity, the similar the surface electronic structure and catalyticperformance in some catalytic reaction of Pt. The WC/TiO2nanocomposite interfacialphotocatalyst was prepared and photocatalytic performance of phenol was invested under UVlight and natural pH. The experimental results show that WC/TiO2exhibited a highphotodegradation activity of phenol and followed the law of pseudo-first-order reactionkinetics, and3w%WC/TiO2showed the highest photocatalytic activity, which outclassedthat of pure P-25and simply mechanical mixing*3w%WC/TiO2. Secondly, after studying the excellent performance of WC comprehensively, to explorethe performance of new synthetic rutile Ti0.7W0.3O2and different Ti0.7W0.3O2loadingproportion of Ti0.7W0.3O2/TiO2nanocomposited interface was constructed, then phenolphotocatalytic performance was studied under the ultraviolet light and natural pH. Theexperimental results show that Ti0.7W0.3O2/TiO2exhibited a high photodegradation activity ofphenol and followed the law of pseudo-first-order reaction kinetics, and5w%Ti0.7W0.3O2/TiO2shows the highest photocatalytic activity.Once again, after fully proving that the rutile Ti0.7W0.3O2can significantly improve thephotocatalytic activity of TiO2, we would like to explore its effect to photocatalyst respondedto visble light further. Therefore, Ti0.7W0.3O2/BiVO4nanocomposite interface loadingdifferent proportion of Ti0.7W0.3O2was constructed, and its photocatalytic performance ofphenol was invested under the visible light irradiation and natural pH. The experimentalresults show that Ti0.7W0.3O2/BiVO4nanocomposite interfacial photocatalyst exhibited highphotocatalytic activity for phenol and also followed the pseudo-first-order reaction kinetics.And5w%Ti0.7W0.3O2/BiVO4shows the highest photocatalytic activity.Finally, all in all, constructing nanocomposite interface is an effective way to improvephotocatalytic performance, and the probable mechanism of phenol photodegradation at theinterface of WC/TiO2,Ti0.7W0.3O2/TiO2and Ti0.7W0.3O2/BiVO4nanocomposite was alsoproposed.