Metal-Oxo Cluster Catalysts for Photocatalytic Water Splitting and Carbon Dioxide Reduction

Photocatalytic water splitting and carbon dioxide photoreduction are considered effective strategies for alleviating the energy crisis and environmental pollution. Polynuclear metal-oxo clusters possess excellent electron storage/release ability and unique catalytic properties via intermetallic synergy, which enables them with great potential in environmentally friendly photosynthesis. Importantly, metal-oxo clusters with precise structure can not only act as high-efficiency catalysts but also provide well-defined structural models for exploring structure–activity relationships. In this review, we systematically summarize recent progress in the catalytic application of polynuclear metal-oxo clusters, including polyoxometalate clusters, lowcost transition metal clusters, and metal-oxo-cluster-based metal–organic frameworks for water splitting and CO2 reduction. Furthermore, we discuss the challenges and solutions to the problems of polynuclear metal-oxo clusters in photocatalysis.