Recent advances in hydrogen production through photocatalytic water splitting: A review

Recently, great attention has been devoted to clean and renewable energy resources due to the environmental concerns and limitations of fossil fuel resources. Hydrogen (H2) has been used widely as a source of clean energy in many applications. H2 can be produced in a clean and cost-effective route, by photocatalytic water splitting. Several semiconductors including TiO2, CdS, ZnS, MoS2, etc. have been used for photocatalytic water splitting. However, their limitations such as charge recombination and inappropriate band gap have persuaded researchers to apply modifications to them to increase their light harvesting and/or charge separation. This paper has reviewed important photocatalysts that are used in photocatalytic H2 production and the recently applied modifications on them are explained. Several types of photocatalyst heterostructures are introduced and novel heterostructures for maximum H2 production rate have been addressed.