Particulate Metal Oxysulfides for Photocatalytic and Photoelectrocatalytic Water Splitting

Narrow bandgap metal oxysulfide photo(electro)catalysts have been extensively investigated as effective candidates for solar energy conversion via water splitting using long-wavelength visible light. Up to now, considerable progress has been achieved over metal oxysulfide photo(electro)catalysts for water splitting. However, compared to metal oxide and metal sulfide photo(electro)catalysts, its performance is still inferior mainly owing to poor control in charge separation and surface catalytic conversion. To address this issue, this review is devoted to presenting a comprehensive illustration of research progress in this field. First, an overview of the fundamentals of photo(electro)catalytic water splitting systems and metal oxysulfides is provided. On this basis, the water splitting performance of representative metal oxysulfides is summarized, together with effective strategies covering material synthesis, surface modification, and system construction. Emphases are especially placed on the aspects of charge separation and surface catalytic reaction, offering promising design perspectives for advancing photo(electro)catalysts and integrated systems based on metal oxysulfides. Future prospects and challenges in developing efficient metal oxysulfide photo(electro)catalysts and their integrated systems are also discussed.