氮钒共掺TiO_2的表征及其对甲醛的可见光催化性能

The characterization of N-V-codoped TiO_2 and its photocatalytic performance of formaldehyde under visible light

以钛酸丁酯为Ti源,六次甲基四胺为N源,偏钒酸铵为V源,利用溶胶-凝胶法制备氮钒共掺杂二氧化钛(N-V-TiO2)纳米材料。采用XRD、UVVis、BET、XPS等检测手段对N-V-TiO2的晶型比例、元素组成等进行分析,研究其在可见光下催化氧化甲醛气体的性能。结果表明,煅烧温度500℃、掺氮28%、掺钒1%的N-V-TiO2具有混晶型结构、比表面积大、对可见光吸收强,催化降解甲醛的效率最高可达到91.6%,分别比纯TiO2、掺氮TiO2、掺钒TiO2的效率显著提高。N-V-TiO2光氧化效率随甲醛初始浓度增大而减小,光催化反应服从一级反应动力学特征,而且包括吸附和光催化氧化反应两部分,其中光催化氧化为速控步骤;重复5次使用的效率仍然高于单独掺杂TiO2。

N-V-codoped nanosized TiO2 powders were prepared by the sol-gel method with tetrabutyl titanate as Ti resource,hexamethylene tetramine as nitrogen resource and ammonium metavanadate as vanadium resource.N-V-TiO2 powders were characterized by XRD,UV-Vis,BET and XPS.The photocatalytic decomposition property of N-V-TiO2 to formaldehyde under visible light was investigated.The results show that the N-V-TiO2 of calcination temperature at 500 ℃,the N-doped amount of 28%,the V-doped amount of 1% has the anatase and rutile mix structure,large specific surface area and strong visible light absorption.The degradation efficiency of formaldehyde was up to 91.6%,which was significantly higher than that of TiO2,N-TiO2 and V-TiO2 respectively.The degradation efficiency of formaldehyde decreased with the increase of its concentration by N-VTiO2 and the photocatalytic reaction was first order and included adsorption and photocatalytic oxidation which was the rate-controlling step.The degradation efficiency after 5times reuse by N-V-TiO2 was still higher than that of N-TiO2 and V-TiO2.