Revisiting solar hydrogen production through photovoltaic-electrocatalytic and photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting is regarded as a promising way for solar hydrogen production, while the fast development of photovoltaic-electrolysis (PV-EC) has pushed PEC research into an embarrassed situation. In this paper, a comparison of PEC and PV-EC in terms of efficiency, cost, and stability is conducted and briefly discussed. It is suggested that the PEC should target on high solar-to-hydrogen efficiency based on cheap semiconductors in order to maintain its role in the technological race of sustainable hydrogen production.