Designing highly efficient and stable photocatalysts is of vital importance for solar-to-fuel conversion, as a potential strategy to address the concerns of global energy crisis and environmental deterioration.The development of novel photocatalytic materials is desirable to overcome those shortcomings of traditional semiconductor photocatalysts.Feng and colleagues report in Nature Communications that two-dimensional gersiloxenes have great potential for photocatalytic H2 evolution and CO2 photoreduction.