Sustainable pollutant removal and wastewater remediation using TiO2-based nanocomposites: A critical review

Rapid industrialization and urbanization emphasized water purification and the production of carbon-neutral fuels. State-of-the-art technology that is low-cost, long-lasting, and easy to implement is required to address these issues. In this context, substantial developments in green synthesis technology have provided a more efficient, effective, and affordable procedure. One possible paradigm worth considering is a circular system that purifies water and produces biomass. Titanium dioxide-based photocatalysts (TPs) can be a great tool due to their outstanding properties, which can be modified for improving photocatalytic activities in various advanced oxidation process applications. In recent years, there has been a significant increase in the attention given to the development of environmentally sustainable TPs. A comprehensive analysis of nearly 300 academic articles in this study has revealed significant shortcomings in effectively utilizing TPs. The primary objective of this paper was to address these gaps that need to be filled in order to ensure the efficient and sustainable utilization of TPs in wastewater treatment. Accordingly, this paper comprehensively reviewed TiO2’s features, including structure, properties, synthesis methods, photocatalytic activities, mechanism, structure modifications, applications, treatment cost analysis, and catalysts reuse in wastewater treatment. Finally, in order to ensure the sustainability of this wastewater treatment technique and achieve the goal of the circular economy, the concept of waste-to-resource has been introduced. The implementation of the aforementioned approach may serve as a valuable means of achieving environmentally sustainable outcomes in the field of wastewater treatment.