Harnessing the Power of Heterogeneous Photocatalytic Process for Sustainable Pharmaceutical Contaminant Remediation in Water Environments

Pharmaceutical pollutants in wastewater can be effectively degraded by heterogeneous photocatalytic processes (HPP); under light irradiation, these methods use semiconductor photocatalysts to produce reactive oxygen species (ROS), which can oxidize and mineralize organic pollutants (OPs) into innocuous byproducts. Reactant transport to the photocatalyst surface, reactant adsorption, charge carrier formation and separation, redox reactions, and product desorption are all part of the photocatalytic mechanisms. This review article analyzes and compares the various approaches used to prepare photocatalysts. The photocatalyst composition, morphology, crystallinity, and production scale, influence the synthesis technique selection. While hydrothermal, microwave-assisted, sonochemical, and mechanochemical processes provide greater variety in synthesising diverse photocatalysts with varying compositions, morphologies, and surface characteristics, flame hydrolysis is appropriate for large-scale production of TiO2 photocatalysts. Because it regulates the photocatalyst's surface charge, the electrolytic solution's pH is significant in photocatalytic processes. Within a certain range, an increase in temperature generally results in a continuous increase in breakdown efficacy; beyond that, the rate of decomposition decreases. These findings besides giving researchers a broad overview of the current status of the HP process we believe will also inform its future applications and advancements.