Ti^(3+)自掺杂TiO_2纳米管/g-C_3N_4复合材料的制备及可见光催化性能

以低温退火制得的TiO_2纳米管和三聚氰胺为原料,经过一步煅烧制备Ti^(3+)自掺杂TiO_2纳米管/g-C_3N_4复合材料.采用热重分析(TGA)、X-射线衍射(XRD)、透射电子显微镜(TEM)、X-射线光电子能谱(XPS)和紫外-可见漫反射光谱(UV-Vis DRS)对Ti^(3+)自掺杂TiO_2纳米管/g-C_3N_4复合材料的热稳定性、组成、结晶性、形貌、化学价态和光学性能等进行了表征.结果表明,将H_2Ti_3O_7预处理后再与三聚氰胺混合热处理,产物是Ti^(3+)自掺杂TiO_2纳米管/g-C_3N_4复合材料,而未经预处理的H_2Ti_3O_7与三聚氰胺混合后热处理得到的是Ti^(3+)自掺杂TiO_2纳米颗粒/g-C_3N_4复合材料.罗丹明B((RhB)水溶液为模拟废水,以300 W氙灯(λ>420 nm)为光源,研究了所得产物的可见光催化降解性能.结果表明,与纯的TiO_2和g-C_3N_4相比,Ti^(3+)自掺杂TiO_2纳米管/g-C_3N_4复合材料具有最佳的光催化降解性能,光催化降解80 min时,对RhB的降解率达98.4%.这得益于Ti^(3+)及TiO_(2-x)纳米管与g-C_3N_4构筑的异质结提高了材料对可见光的响应性能,加快了光生电子的传输和分离,降低了电子和空穴的复合几率.

Facile synthesis of S-doped reduced TiO_(2-x) with enhanced visible-light photocatalytic performance

A different approach to synthesize visible‐light‐active sulfur(S)‐doped reduced titania(S‐TiO2‐x)using thiourea dioxide as both the S source and reductant was developed.The structure,morphology,and optical and electronic properties of the as‐prepared S‐TiO2‐x samples were examined by multiple techniques,such as X‐ray diffraction,transmission electron microscopy,X‐ray photoelectron spectroscopy,ultraviolet‐visible diffuse reflectance spectroscopy,Brunauer‐Emmett‐Teller and photocurrent measurements,and electrochemical impedance spectroscopy.The photocatalytic activity of S‐TiO2‐x was evaluated by photodegradation of organic Rhodamine B under visible‐light irradiation.The degradation rate of Rhodamine B by S‐TiO2‐x obtained by calcination was about31,2.5,and3.6times higher than those of pure TiO2,pristine TiO2‐x,and S‐doped TiO2,respectively.In addition,the as‐prepared S‐TiO2‐x exhibited long‐term stable photocatalytic performance in the degradation of Rhodamine B under visible‐light illumination.This report reveals a new approach to prepare stable and highly efficient solar light‐driven photocatalysts for water purification.