Advancements in Large‐Area Photoelectrochemical Water‐Splitting Devices: A Mini‐Survey of Photoelectrode Materials for Commercial Viability

ABSTRACT The increasing impacts of global warming, driven by carbon emissions from fossil fuels, have intensified the need for sustainable energy systems. Photoelectrochemical (PEC) water splitting offers a promising route for solar‐driven hydrogen production. This work highlights recent advancements in photoelectrode materials tailored for large‐area PEC devices, defined by illumination areas exceeding 50 cm 2 . The selection of photoelectrode materials with optimal bandgaps and stability is critical for enhancing solar‐to‐hydrogen (STH) efficiency, scalability, and operational robustness. Key modification strategies such as doping, surface engineering, nanostructuring, and heterostructure formation have shown promise in addressing challenges like limited light absorption, charge recombination, and electrode degradation. Integrating co‐catalysts and innovative structures, such as Z‐scheme heterojunctions, enhances performance. Nonetheless, achieving uniformity and cost‐effective production for large‐scale applications remains a challenge. Emerging methods that utilize machine learning and large‐scale computational screening show promise in speeding up material discovery and optimizing device architectures. Future efforts should focus on eco‐friendly, scalable solutions to drive the commercialization of PEC technologies for clean hydrogen production.