Exploring critical development in photocatalytic overall Water splitting: Recent trend, Current Challenges and Prospects

Despite intensive research on solar-driven photocatalytic overall water splitting (OWS), the overall efficiencies remain insufficient to meet commercial standards. As central challenge in realizing this technology mainly lies in the precise tuning and rational designing of highly efficient materials and photocatalytic system, which is paramount for unlocking scalable, practical applications. However, novel materials fabrication and advanced photocatalytic systems is essential for overcoming intrinsic limitations of conventional catalysts by enabling this green technology to resolve global energy crisis. Therefore, this review critically explores the engineering developments in (OWS) process and novel photocatalyst designing, via shifting from simple bandgap engineering to more advanced charge carrier dynamics control via utilizing one/two-step photocatalytic excitation system, surface phase junctions i.e., Z-scheme and S-scheme heterojunctions, surface modification, morphological tuning, along with the role of co-catalysts, to control sluggish kinetic, promote four-hole oxygen evolution reaction (OER) and suppressing undesirable H₂/O₂, backward reaction with superior visible light absorption capacity to produce remarkable energy production. Moreover, we critically, discuss the recent trend of OWS from a materials discovery phase to demanding engineering and mechanistic optimization phase with viable economic viability, which requires bridging the gap between excellent lab-scale performance to stringent stability, cost, and high efficiency demands of industrial-scale solar fuel production with more beneficial systems. In addition, the currents challenges and future directions are also enclosed in detail for sustainable energy production.