Graphene-based TiO2 photocatalysts for water decontamination: a brief overview of photocatalytic and antimicrobial performances

This article highlights the major accomplishments in photocatalytic research and reported-antimicrobial acti­vities of graphene-based titanium dioxide (TiO2) hybrids. Special focus is given to the applications of TiO2–gra­phene and its major forms (TiO2–graphene oxide and TiO2–reduced graphene oxide) in wastewater treatments. Particularly, for systems envisaged for removing emerging micro-pollutants and microbial pathogens in real-life scenarios. The efficiency of the photocatalysts is found to be influenced by several factors, including the surface, chemical, morphological and interfacial characteristics of the hybrids. The mode of interaction of catalysts with pollutants, the percentage of graphene content and the nature of irradiation sources could alter the expected photocatalytic efficacy. It is concluded that the incorporation of graphene in TiO2 improves its photocatalytic performance by boosting photo-responsiveness and sup­pressing electron–hole recombination. The oxidative stress by reactive oxygen species and membrane stress due to the material’s physico-chemical properties account for the observed antimicrobial activities under controlled conditions of light irradiation.