A review on the applications of zinc tungstate (ZnWO ₄) photocatalyst for wastewater treatment

Abstract

The monoclinic wolframite-phase structure of ZnWO ₄ materials has been frequently synthesised, characterised, and applied in optical fibres, environmental decontamination, electrochemistry, photonics, catalysis, and not limited to magnetic applications. However, the problems of crystal growth conditions and mechanisms, growth, the crystal quality, stability, and the role of synthesis parameters of ZnWO ₄ nanoparticles remain a challenge limiting its commercial applications. This review presents recent advances of ZnWO ₄ as an advanced multi-functional material for Industrial wastewater treatment. The review also examines the influence of the synthesis parameters on the properties of ZnWO ₄ and provides insight into new perspectives on ZnWO ₄-based photocatalyst. Many researches have shown significant improvement in the efficiency of ZnWO ₄ by mixing with polymers and doping with metals, nonmetals, and other nanoparticles. The review also provides information on the mechanism of doping ZnWO ₄ with metals, non-metals, metalloids, metals oxides, and polymers based on different synthesis methods for bandgap reduction and extension of its photocatalytic activity to the visible region. The doped ZnWO ₄ photocatalyst was a more effective and environmentally friendly material for removing organic and inorganic contaminants in industrial wastewater than ordinary ZnWO ₄ nanocrystalline under suitable growth conditions.

Abstract

Nanoparticles; Photocatalyst; Doping; Bandgap; Pollutants.