Recent advances in degradation of pharmaceuticals using Bi2WO6 mediated photocatalysis – A comprehensive review

The pollution of water bodies by residual pharmaceuticals is a major problem globally. Bismuth tungstate mediated photocatalysis has been effective in the removal of these organics from water. Bismuth tungstate (Bi2WO6) has proven to be an excellent visible light active photocatalyst because of its non-toxicity, low band gap energy and ease of preparation. It has been widely applied for the removal of a wide array of organic pollutants, particularly dyes, from wastewater. However, recently, much attention has been channelled to its application for the degradation of pharmaceuticals. In this present review, the recent trends in the applications of Bi2WO6 based photocatalysts for the removal of pharmaceuticals in wastewater are comprehensively discussed. The fabrication of Bi2WO6 based photocatalysts with enhanced photocatalytic performances through morphology control, doping and formation of heterojunctions are highlighted. Much discussion centres on the mechanisms and possible degradation pathways of antibiotic pharmaceuticals in wastewater. Finally, areas needing more attention and investigation on the use of Bi2WO6 based photocatalysts for removal of pharmaceuticals from wastewater especially towards real-life applications are presented for future research directions.