“GREEN HYDROGEN” VIA PHOTOELECTROCATALYSIS

Abstract: The growing global demand for clean and sustainable energy sources has intensified interest in green hydrogen as a carbon-free fuel. Among the various pathways for green hydrogen generation, photoelectrocatalysis (PEC) has gained significant attention due to its unique ability to directly convert solar energy into chemical energy through water splitting. This review provides a comprehensive overview of recent progress in PEC-driven hydrogen production. Key classes of photoelectrocatalysts—including metal oxides, chalcogenides, perovskites, and emerging two-dimensional materials—are analyzed with respect to their optical absorption, band alignment, stability, and catalytic activity. Challenges such as limited light absorption, rapid charge recombination, corrosion, and scalability constraints are critically discussed. Finally, future directions for achieving commercially viable PEC hydrogen generation are outlined, earth-abundant catalysts and systems engineering approaches. Overall, this review underscores the potential of photoelectrocatalysis as a promising pathway for large-scale green hydrogen production powered by sunlight.