Driving sustainable energy: The role of polyoxometalates (POMs) in photoelectrochemical hydrogen production

This review elucidates the pivotal role of polyoxometalates (POMs) in photoelectrochemical (PEC) water splitting, an emerging field with profound implications for sustainable hydrogen production. POMs, characterized by their versatile metal oxide clusters, exhibit remarkable efficacy as co-catalysts, enhancing the efficiency and performance of PEC systems. Through precise modulation of charge separation dynamics and promotion of efficient charge transfer kinetics at the semiconductor-electrolyte interface, POMs significantly augment the overall efficiency of PEC devices. Their inherent attributes, including broad-spectrum light absorption and exceptional chemical stability, underscore their suitability for solar-driven electrolysis, offering a viable pathway towards sustainable hydrogen generation. This review underscores the strategic importance of POMs in optimizing the functionality of key semiconductors employed in PEC, such as BiVO4, CdS, Si, Fe2O3, and TiO2, thereby advancing the frontiers of renewable energy conversion technologies. Additionally, the exploration of innovative strategies for enhancing POM-based photoelectrodes, encompassing tailored surface modifications and synergistic tandem cell configurations, underscores the indispensable role of POMs in catalyzing the transition towards efficient and scalable hydrogen production methodologies. •The strategic importance of POMs in optimizing the functionality of key semiconductors employed in photoelectrochemical water splitting.•The exploration of innovative strategies for enhancing POM-based photoelectrodes.•The indispensable role of POMs in catalyzing the transition towards efficient and scalable hydrogen production methodologies.