Harnessing visible light: Advanced photocatalytic strategies for sustainable environmental reactions

Climate change and water pollution pose serious threats to environmental sustainability, driving the need for greener and more efficient treatment technologies. Visible-light-driven photocatalysis has emerged as a promising strategy for harnessing solar energy to drive key environmental reactions. This critical review explores advanced approaches to enhance the efficiency of sustainable photocatalytic reactions, including CO₂ reduction, H₂ generation, and organic pollutant degradation. Strategies such as bandgap engineering, heterostructure formation, surface plasmon resonance enhancement, hybrid advanced oxidation processes, dye sensitization, and reactor design optimization were discussed in the context of improving solar-driven photocatalysis. Importantly, this review highlights recent breakthroughs in material design, including atomically engineered interfaces and defect-modulated photocatalysts, which significantly enhance light absorption and charge carrier separation. Notably, this review represents the first critical review to offer a holistic perspective on visible-light-driven photocatalysis, systematically integrating material innovation and system-level engineering across several key environmental applications. Additionally, challenges in solar photocatalysis and innovative reactor designs for improved scalability and efficiency are examined. In conclusion, this review presents a unified framework combining advanced photocatalytic materials with system-level engineering to drive solar H₂ generation, CO₂ conversion, and pollutant degradation. It emphasizes scalable, stable designs, sustainable synthesis, and efficient light use through heterojunctions, dye sensitization, and hybrid systems.