Application of polyoxometalates and their composites for the degradation of antibiotics in water medium

This paper summarizes the potential of polyoxometalate (POM)-based catalysts in view of pharmaceutical wastewater treatment and recent advances that took place in this field. POMs are anionic clusters of transition metals, which exhibit unique characteristics such as high catalytic activity and multi-electron redox properties. Recently, they have been explored by some research groups for degrading antibiotics and pharmaceutical compounds (PCs) from contaminated water matrix. Several modifications of POM, along with their composite formation with new-age materials like g-C3N4 and reduced graphene oxide (RGO), have led to the formation of novel photocatalysts, which have also been reported as active materials to destroy the PCs. These promising catalysts have revealed the efficiency of complete destruction of these recalcitrant compounds within a short reaction time and showed good reusability characteristics. Among the widely used PCs, the notable ones include tetracycline (TC), sulfamethoxazole (SMX), ciprofloxacin (CIP), etc. Most of the articles cited here centered on TC degradation followed by other drugs. The effects of different operating conditions, degradation efficiency, and mechanism and stability aspects of various POM-based catalysts are discussed. The current knowledge gap in this area with bright future perspectives is also highlighted. The description will provide valuable insight to the research community regarding the capability of POM-based catalysts to eliminate antibiotics, as well as designing highly efficient catalysts for a sustainable future.