Recent advances in dye-sensitized semiconductor systems for photocatalytic hydrogen production

Photocatalytic water splitting by solar light has received tremendous attention for the production of clean and renewable hydrogen energy from water. Some challenges still remain in improving the solar-to-hydrogen energy conversion efficiency, such as utilizing longer-wavelength photons and enhancing the photocatalytic activity and stability of H-2 production over semiconducting materials. Dye sensitization, as a successful strategy for extending the spectral responsive region (even to near-IR light) of wide bandgap semiconductors for H-2 production, was developed more than 30 years ago, but it still lacks the corresponding specialized review. This review emphasizes especially the fundamental aspects and the research advances in heterogeneous dye-sensitized semiconductor suspension systems for visible (and even near-IR) light responsive photocatalytic H-2 production, and the commonly used dyes, semiconductors, co-catalysts and electron donors are systematically discussed. Also, a short perspective on the challenges and new directions in this field is proposed, which would be of great interest in the field of solar fuel conversion.