新型光催化剂AgAlO₂的电子结构与光催化表征

Electronic structure and photocatalytic characterization of a novel photocatalyst AgAlO2.

作者信息

Ouyang Shuxin, Zhang Haitao, Li Dunfang, Yu Tao, Ye Jinhua, Zou Zhigang

机构信息

Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, PR China.

出版信息

J Phys Chem B. 2006 Jun 22;110(24):11677-82. doi: 10.1021/jp055924t.

DOI:10.1021/jp055924t

PMID:16800462

Abstract

A novel photocatalyst, AgAlO2, was prepared by cation exchange reaction and characterized by powder X-ray diffraction. The result showed AgAlO2 crystallizes in the layered orthorhombic structure with space group was Pna2(1). The energy band and electronic structures of AgAlO2 were calculated based on the crystal structure. It was found that AgAlO2 is an indirect band gap semiconductor. The valence band top mainly consists of O-2p orbitals and Ag-4d orbitals and the conduction band bottom is mainly constructed of Ag-5s5p orbitals. The band gap of AgAlO2 was estimated to be about 2.8(1) eV with UV-vis diffuse reflectance spectrometry. The photocatalytic activity of AgAlO2 was characterized by photocatalytically decomposing the dye alizarin red (AR) under visible light irradiation, and AR could be decomposed about 70% under 2 h of visible light irradiation.

摘要

通过阳离子交换反应制备了一种新型光催化剂AgAlO₂，并采用粉末X射线衍射对其进行了表征。结果表明，AgAlO₂以层状正交结构结晶，空间群为Pna2(1)。基于晶体结构计算了AgAlO₂的能带和电子结构。发现AgAlO₂是一种间接带隙半导体。价带顶主要由O-2p轨道和Ag-4d轨道组成，导带底主要由Ag-5s5p轨道构成。用紫外-可见漫反射光谱法估计AgAlO₂的带隙约为2.8(1) eV。通过在可见光照射下光催化分解染料茜素红(AR)来表征AgAlO₂的光催化活性，在可见光照射2 h下，AR可分解约70%。