Comparative study of photocatalytic activity of metals- and non-metals doped ZnO and TiO2 nanocatalysts for advanced photocatalysis

Abstract

This review article provides useful information on TiO2 and ZnO photocatalysts and their derivatives in removing organic contaminants such as different types of dyes, hydrocarbons, pesticides, etc. Also, the reaction mechanism of TiO2 and ZnO photocatalysts and their derivatives was investigated. In addition, the impact of adding metallic (e.g., Ag, Co, Pt, Pd, Cu, Au, Ni) and non-metallic (e.g., C, N, O, S) dopants to their structure on the photodegradation efficiency of organic compounds was thoroughly studied. Moreover, advantages and disadvantages of various synthesis procedures of ZnO and TiO2 nanocatalysts were discussed and compared. Furthermore, the impact of photocatalyst dosage, photocatalyst structure, contaminant concentration, pH, light intensity and wavelength, temperature and reaction time on the photodegradation efficiency was studied. According to previous studies, adding metallic and non-metallic dopants to the TiO2 and ZnO structure led to a remarkable enhance in their stability and reusability. Besides, doped TiO2 and ZnO demonstrated remarkable photocatalytic efficiencies in eliminating various types of organic contaminants.