氮化碳改性二氧化钛增强可见光催化活性  

Enhanced Visible Light Photocatalytic Activity of TiO_2 Modified by Carbon Nitride

作　　者：周建伟[1] 褚亮亮[1] 王储备[1] 李风彩 

机构地区：[1]新乡学院能源与燃料研究所,河南新乡453003 [2]新乡学院化学化工学院,河南新乡453003

出　　处：《新乡学院学报》2016年第12期21-26,共6页Journal of Xinxiang University

基　　金：新乡市重点科技攻关项目(ZG15022);新乡学院科技创新基金项目(15ZP05)

摘　　要：采用溶胶-凝胶法及焙烧处理制备了g-C_3N_4/TiO_2复合光催化材料,利用多种分析手段进行了结构与性能表征。研究表明,在n(N):n(Ti)=3.5、焙烧温度580℃条件下制备的样品光催化降解染料亚甲基蓝,在紫外光与可见光照射下的催化反应速率常数分别是纯TiO_2的1.2倍、纯g-C_3N_4的3.1倍。通过XPS和HR-TEM分析可知,凝胶中三聚氰胺的热解使N和C原子扩散到TiO_2晶格中,形成了g-C_3N_4-TiO_2异质结。紫外-可见漫反射分析显示,g-C_3N_4掺杂使TiO_2光吸收范围扩展至可见光区,光催化活性提高的主要原因归结于:形成g-TiO_2-TiO_2异质结和TiO_2的锐钛矿与金红石特殊相界的协同作用。The g-C3N4/TiO2 composites were prepared via a facile sol-gel followed by a simple calcination process. The obtained g- C3N4/TiO2 composite products were well characterized by various analytical techniques. The results revealed that with the mole ratio of n（N）：n（Ti）=3.5, and the calcination temperature 580℃, the rate constants for catalytic reactions of sample light processed for degrading methylene blue under UV light and visible-light irradiation were respectively 1.2 times and 3.1 times higher than that of the pure TiO2 and g-C3N4. By XPS and HR-TEM analysis, N and C diffuse into the lattice of TiO2, and meanwhile there was heterojunction formation of g-C3N4-TiO2 via pyrolysis of melamine. UV-Vis analysis showed that the responsive wavelength range of doped TiO2 was extended to the visible-light region. The enhanced activitiy of g-C3N4/TiO2 could be primarily attributed to the synergetic effects of two factors including the formation g-C3N4-TiO2 heterojunction and the special interphase between anatase and rutile phases, where photo-generated electron-hole pairs were efficiently separated in space, whose synergistic effect was beneficial for retarding the charge recombination and improving the photocatalytic activity.

关 键 词：二氧化钛 氮化碳 异质结 协同作用 光催化 

分 类 号：O643.36[理学—物理化学]