Oxygen vacancy modification of commercial ZnO by hydrogen reduction for the removal of thiabendazole: Characterization and kinetic study

Abstract

The effect of temperature-programmed H2 reduction on modification of surface oxygen vacancies in commercial ZnO (C-ZnO) is investigated. The photocatalytic degradation of the fungicide thiabendazole was optimized by treating C-ZnO with 10% H2/Ar gas at 500 °C over 5 h. The formation of oxygen vacancies and their catalytic activity were compared before and after the reduction treatment based on their characterization analysis (e.g., TPR, FE-SEM, EDS, XPS, Tauc plot, XRD, and BET). Our most recent kinetic modeling was carried out on the experiments using C-ZnO and T500 at different pH values. The highest adsorption removal and photocatalytic degradation rate (and quantum yield) was occurred at pH 3 and 11, respectively. Good reusability of the optimal reduced catalyst was confirmed when tested over five cycles. A strong compatibility between the kinetic modeling results and all characterization analyses supports the potent role of reduction treatment for the modification of oxygen vacancies on photocatalysis.