Photocatalysis performance enhancement of Ag2O/Al-doped ZnO heterojunction by introducing ZnO nanorod array

Abstract

Fabric-based nano semiconductor photocatalysts have attracted much attention in recent years. In this study, polyester fibers were modified by Ag2O/ZnO nanorod (NR)/Al-ZnO p-type/high resistivity/n-type (P-HR-N) heterojunction arrays. Al-doped ZnO (Al-ZnO) seed layer was reactively sputtered on polyester fibers. Al doping was used to change the work function (WF) of the ZnO film. The ZnO NR arrays were hydrothermally grown on the Al-ZnO seed layer and modified with Ag2O film. The work functions (WFs) of Ag2O and Al-ZnO layers were measured, resulting in 5.53 and 4.81eV, respectively. The WF difference between the two layers was 0.72eV. The electron-hole separation of the P-HR-N heterojunction array was characterized by surface photovoltage (SPV) spectra. The photocatalytic activities of the prepared samples were investigated by removing Rhodamine B (RB) under UV irradiation. The P-HR-N heterojunction sample displayed a better photocatalytic performance than the Ag2O/Al-doped ZnO PN heterojunction sample and ZnO NR/Al-ZnO array-coated sample. The enhanced photocatalytic performance of the P-HR-N heterojunction based sample was mainly attributed to the high and widened built-in electric field (BEF) in the multilayer film.