Advancements in the zinc oxide nanomaterials for efficient photocatalysis

Zinc oxide photocatalyst with multifaceted and tunable structure-electronic properties has garnered foremost relevance in the wastewater purification. The drawbacks supplemented with ZnO such as wide band gap, immense charge carrier recombination and photo-corrosion (deactivation) during the photocatalytic reactions obfuscate for large scale applications. Accordingly, research is swiftly inclining to spotlight the ZnO as an appropriate semiconductor to many competitive metal oxides (TiO2, Bi2O3 and WO3) in the area of heterogeneous photocatalysis. In this focused review, several strategies like synthesizing with hierarchical morphology and exposed facets, impurity doping, metal deposition, integrating with other semiconductors and modifying with carbon materials which induces multifunctional properties to boost the performance of ZnO are articulated. It is presumed that the photocatalytic activity of the modified ZnO arises from the collective contribution of effective charge carrier separation, generation of surplus active free radicals coupled with striking structure-electronic properties and nature of the photocatalytic reactions. The overall findings enunciate that such amendments to ZnO are beneficial to improve structural stability and also to obtain desired features driving for various energy applications.