摘要
采用电沉积和旋转涂膜相结合的方法成功制备了高度有序的TiO2/Au纳米棒阵列催化剂.扫描电镜和透射电镜结果表明,TiO2薄膜均匀地包覆在Au纳米棒的表面,形成核壳型的一维阵列结构.X射线衍射分析表明所获得TiO2为（101）晶面优先生长的锐钛矿晶相.紫外-可见漫反射光谱显示,由于Au和TiO2间肖特基结的存在造成吸收红移,Au纳米棒表面的等离子共振效应导致400~800nm间出现吸收峰.在紫外光催化降解罗丹明B反应中,TiO2/Au纳米棒阵列催化剂表现出优异的催化活性,其动力学常数分别为TiO2和TiO2/Au膜的2.0和1.3倍.这主要归结于Au与TiO2间的肖特基结和一维阵列结构所带来的大的比表面积、宽的光响应范围和有效的光生载流子分离与传递.
A highly ordered TiO2/Au nanorod array was successfully fabricated by direct current electrodeposition and subsequent spin-coating. Scanning electron microscopy and transmission electron microscopy images revealed that the TiO2 film completely covered the surface of the Au nanorods, which resulted in TiO2 shell Au core nanorods. X-ray diffraction patterns revealed that the TiO2 film was anatase with preferential orientation in the （101） plane. UV-Vis diffuse reflectance spectra showed a shift in the absorption edge toward the visible region because of the formation of a Schottky junction between Au and TiO2. A new absorption peak that ranged from 400 to 800 nm appeared because of the localized surface plasmon resonance of the Au nanorod arrays. For the photocatalytic degradation of rhodamine B under UV light irradiation, the TiO2/Au nanorod array exhibited excellent photocatalytic activity and its kinetic constant was 2.0 times that of pristine TiO2 and 1.3 times that of a TiO2/Au film. The enhanced photocatalysis was attributed to the high surface volume ratio, an improved UV light response, efficient separation, and the convenient migration of photogenerated charge carriers because of the one-dimensional nanorod structure and the Schottky junction between Au and TiO2. This work could provide new insights into the fabrication of a high performance photocatalyst and thus facilitate practical environmental applications.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2011年第12期1838-1843,共6页
基金
supported by the National Natural Science Foundation of China(20837001 and 21077018)
the Program for Changjiang Scholars and Innovative Research Team in University(IRT0813)~~
关键词
二氧化钛
金纳米棒阵列
肖特基结
光生载流子分离
光生载流子迁移
光催化活性
titania
gold nanorod array
Schottky junction
photogenerated charge carrier separation
photogenerated charge carrier migration
photocatalytic activity
