Achieving long-term durability in solar water splitting: a comprehensive review of degradation mechanisms and stabilization strategies

초록

The global pursuit of carbon neutrality has catalyzed the development of solar water splitting technologies, including photovoltaic-electrochemical (PV-EC), photoelectrochemical (PEC), and particulate photocatalysis (PC) systems, as a sustainable route for green hydrogen production. While solar-to-hydrogen (STH) conversion efficiencies have recently surpassed 20%, the field faces a critical challenge: long-term operational stability. State-of-the-art devices often degrade within tens of hours, far short of the 1,000 to 10,000-hour requirement for commercial viability. This review provides a systematic, mechanism-driven analysis of degradation pathways, including thermodynamic instability, photocorrosion, and electrolyte-driven dissolution, highlighting the inherent dilemma in which optimal light-harvesting properties often render materials vulnerable in corrosive environments. To address these failure modes, we evaluate four primary stabilization pillars: protective coatings to isolate absorbers physically, interface engineering to accelerate charge-transfer kinetics relative to self-oxidation rates, self-healing systems that utilize dynamic regeneration for in situ repair, and electrolyte optimization to suppress corrosion thermodynamically. By unifying these mechanistic insights and engineering strategies, this work establishes a strategic roadmap to bridge the gap between laboratory-scale efficiency and the industrial durability needed to make solar hydrogen a practical energy reality.

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