Latest progress in hydrogen production from solar water splitting via photocatalysis, photoelectrochemical, and photovoltaic-photoelectrochemical solutions

Hydrogen production via solar water splitting is regarded as one of the most promising ways to utilize solar energy and has attracted more and more attention. Great progress has been made on photocatalytic water splitting for hydrogen production in the past few years. This review summarizes the very recent progress (mainly in the last 2–3 years) on three major types of solar hydrogen production systems: particulate photocatalysis (PC) systems, photoelectrochemical (PEC) systems, and photovoltaic-photoelectrochemical (PV-PEC) hybrid systems. The solar-to-hydrogen (STH) conversion efficiency of PC systems has recently exceeded 1.0% using a SrTiO3:La,Rh/Au/BiVO4:Mo photocatalyst, 2.5% for PEC water splitting on a tantalum nitride photoanode, and reached 22.4% for PV-PEC water splitting using a multi-junction GaInP/GaAs/Ge cell and Ni electrode hybrid system. The advantages and disadvantages of these systems for hydrogen production via solar water splitting, especially for their potential demonstration and application in the future, are briefly described and discussed. Finally, the challenges and opportunities for solar water splitting solutions are also forecasted.