Bimetallic cocatalysts for photocatalytic hydrogen production from water

Photocatalytic hydrogen (H2) production from water is a promising technology toward sustainability. The development of efficient and stable photocatalysts has been the key to the wide application of this technology. Metal cocatalysts have played essential roles in enhancing the performance of general semiconductor photocatalysts. Compared to the mono-metallic cocatalysts, bimetallic cocatalysts demonstrate exceptional synergetic phenomena that could dramatically enhance the catalytic activity and stability. Herein, after a brief introduction of the basic principle of photocatalytic water splitting for H2 generation, the typical structures, synthesis methodologies, screening criteria and recent progresses of bimetal cocatalysts, including bi-noble-metal, noble-non-noble, and bi-none-noble metal ones, for photocatalytic H2 production from water are discussed successively. The synergetic effects in the bimetallic systems and the factors (including the elemental composition, overall metal loading, structure and particle size, etc.) that influence the material properties and catalytic activities are highlighted. At last, the current challenges and future opportunities in upgrading bimetallic cocatalyst for highly efficient photocatalytic H2 evolution from water are addressed. The work is expected to trigger accumulative endeavors to drive the practical application of photocatalytic technology for sustainable H2 generation.