Function-oriented bifunctional Mg & MoP modified polymeric carbon nitride for selective photoreduction CO2 to CH4

Constructing photocatalysts with dual-function active sites can coordinate the photogenerated electrons transfer and the adsorption energy of key intermediates, thereby converting CO2 into valuable methane with high efficiency. However, the role that the interfacial position of functional catalysts played in determining the activity and selectivity of CO2 photoreduction remains unclear. Herein, we regulated the action interface and synergistic effect of magnesium nitrate hydroxide and molybdenum phosphide (Mg & MoP) to modify polymeric carbon nitride (PCN), and found the function-oriented Mg-MoP/PCN exhibits superior performance for catalyzing CO2-to-CH4 in pure water, with a rate of 24.45 μmol h−1 g−1 and 95.3 % selectivity. Theoretical and experimental studies reveal that interfacial layer of MoP promotes the evolutionary activity by facilitating the electron transfer while exterior layer of Mg functions as the catalyzing sites to tackle the selectivity challenge by promoting CO2 adsorption and CO* stabilization. The synergistic interaction of function-oriented Mg&MoP realizes selective CH4 evolution with high efficiency via a Z-scheme pathway. The interfacial position of bifunctional catalysts is vital for regulating CO2 photoreduction activity and product selectivity.