The mesoporous Ti O2 has been synthesized by evaporation induced self assembly(EISA) method. The thermogravimetric/differential scanning calorimetric(TG/DSC), X-ray diffraction(XRD), high-resolution transmission electron microscopy(HR-TEM) and N2 adsorption desorption and adsorption are used to study the effects of the synthesized process condition on the microstructure of the as-synthesized mesoporous Ti O2. The photocatalytic performances of as-synthesized samples are evaluated by the degradation of the formaldehyde under ultraviolet light irradiations. The results demonstrate that the as-synthesized mesoporous Ti O2 are anatase with the uniform size about 20-40 nm. The sample is prepared using cetyltrimethyl ammonium bromide(CTAB) as the template with average pore size distribution of 8.12 nm, specific surface area of 68.47 m2/g and pore volume of 0.213 m L/g. The samples show decomposition of formaldehyde 95.8% under ultraviolet light irradiations for 90 min. These results provide a basic experimental process for preparation mesoporous Ti O2, which will posses a broad prospect in terms of the applications in improving indoor air quality.
Surface heterojunction engineering has been extensively studied to promote efficient charge separation in semiconductor materials.Designing an effective heterojunction system to optimize the separation and transport of photo-induced charges is an appealing strategy to enhance the photocatalytic efficiency.In this work,In_(2)O_(3)-x(OH)y in situ decorated Bi_(2)MoO_(6) two-dimensional step-scheme heterojunctions were synthesized through a controlled dehydroxylation process of indium-based precursors.The charge transfer mechanism of this step-scheme heterojunctions was confirmed by the characterization of electron structures,reactive species,photoelectric properties and DFT theoretical calculation.The band bending and the internal electric field caused by the charge transfer upon hybridization can effectively promote the separation of charges and present the optimal redox capacity.In addition,surface residual hydroxyl groups can regulate the surface energy state and optimize the interfacial charge transfer kinetics of the prepared step-scheme heterojunction.Eventually,the step-scheme heterojunction exhibits superior performance in photocatalytic reduction of hexavalent chromium and degradation of organic pollutants under visible light irradiation.This work provides an innovative perspective to construct photocatalyst with superior activity.
选用与In元素离子半径相近的W为掺杂元素,采用溶胶–凝胶法制备了W掺杂的Li In O_2(W:Li In O_2)光催化剂,研究不同W掺杂量对W:Li In O_2样品光催化活性的影响,并探索其增强的可见光催化机理。结果表明:W^(6+)成功进入了Li In O_2晶格并部分取代了In^(3+),导致W:Li In O_2的光吸收边产生了明显的红移,禁带宽度由3.6 e V降至3.3 e V。当W掺杂量为6%(摩尔分数)时,W:Li In O_2表现出最高的可见光(λ>420 nm)光催化降解亚甲基蓝染料的活性,其降解率在90 min内达到了100%,远高于纯Li In O_2样品的57%。W:Li In O_2增强的可见光催化活性主要归因于W掺杂提高了催化剂对光的利用率以及促进了光生电子–空穴对的有效分离。
