Engineering advances and prospects in photoelectrochemical oxidation/reduction processes for the elimination of pharmaceutically active compounds

The ubiquitous presence of pharmaceutically active compounds (PhACs), a major class of contaminants of emerging concern in water sources poses serious environmental and health risks (e.g., promotion of antibiotic-resistant bacteria). Conventional wastewater treatment systems are unable to completely remove these micro-pollutants, leading to their continuous release into aquatic environments. Advanced remediation strategies are therefore needed. Among these, electrochemical oxidation (EO) and photocatalytic processes have been widely studied for PhAC degradation; however, each of these techniques alone still faces limitations such as high operational costs or incomplete mineralization. This review focuses on the emerging synergy of EO and photocatalysis in integrated photoelectrochemical (PEC) systems to overcome those challenges. We critically evaluate recent engineering advances in PEC photoelectrode materials, elucidate the oxidative and reductive degradation pathways involved, and assess overall system performance. Particular attention is given to scale-up considerations, cost-effectiveness, and environmental impacts (notably the formation and toxicity of by-products). By identifying key knowledge gaps and technical hurdles, this review provides a comprehensive, forward-looking perspective on the prospects of PEC-based processes for effective PhAC elimination in wastewater treatment. ● Reviews PEC synergy of electrochemical AOPs and photocatalysis for PhACs ● Maps photoelectrode advances: heterojunctions, doping, piezo-phototronics ● Assesses anodic+cathodic co-oxidation routes and energy/performance metrics ● Highlights durability gaps in real wastewater; calls for standardized tests ● Outlines scale-up pathways and low-cost electrode fabrication from wastes