Impact of Structural Defects on the Photocatalytic Properties of Zno

Abstract

ZnO photocatalytic materials have been prepared using three precursors (Zinc Acetate, Zinc Hydroxide, and Zinc Peroxide), and the effect of calcination temperature on structural and photocatalytic properties of ZnO have been investigated. XRD, UV-Vis, BET, XPS, Time Resolved Microwave Conductivity (TRMC), Raman, and Electron Paramagnetic Resonance (EPR) have been used to correlate the impact of the surface area, the introduction of oxygen and/or zinc vacancies, and the charge carrier dynamics, with their photocatalytic properties. The main objective is to provide a new approach to the impact of structural defects on ZnO semiconductors determined by using Raman and EPR techniques, and by coupling with the important role of the surface area considered as one of the most relevant characteristics in photocatalysis in terms of performance. The fewer surface defects, the more photoactive the catalyst is. The results are discussed for the model degradation of formic acid and phenol under UV-irradiation.

Keywords: zinc oxide, photocatalysis, Surface area, structural defects, Electron Paramagnetic Resonance (EPR)