Tailored ZnO/CuS nanoarchitectures self-assembled in natural deep eutectic solvents for enhanced photocatalytic degradation of noxious water contaminants

Abstract

The photocatalytic properties of catalysts invariably rely on their morphological and electronic attributes. Accordingly, several strategies focused on affecting these two properties have been developed to improve the performance of photocatalytic systems. However, almost every one of those strategies employs cost-intensive chemical modification, which in most cases is environmentally hazardous. In this article, we have demonstrated the effect of natural deep eutectic solvents (NaDESs) in fine tuning the morphological and electronic attributes of a model photocatalyst, ZnO:CuS nanocomposite. Typically, a series of ZnO:CuS catalysts were designed by processing in varied concentrations of urea: fructose and urea: glucose NaDESs. The developed systems were adequately characterized and ZnO:CuS/U:G-1 system displayed best morphological, electronic and surface potential properties. Subsequently, ZnO:CuS/U:G-1 system also showed best photocatalytic performance towards both model water contaminants, tetracycline hydrochloride and malachite green. Importantly, the photocatalytic performance of this ZnO:CuS/U:G-1 system was also compared with ZnO:CuS prepared in conventional solvents like water and ethylene glycol and significant improvement in the morphological, electronic and photocatalytic properties was observed. This presented study shows that how a simple solvent-based strategy can induce changes of significant magnitude, which are otherwise difficult to achieve in a cost-effective and environmentally benign manner.