Advances in molybdenum-containing photocatalysts for nitrogen fixation

The reduction of N₂ to ammonia is a primary pathway for artificial nitrogen fixation. The use of photocatalysts to achieve this reduction is currently considered as an environmentally friendly and efficient approach. However, one of the major challenges in photocatalytic nitrogen fixation is the adsorption of N₂ onto the catalyst surface and the subsequent electron transfer for reduction. Molybdenum (Mo) has garnered significant attention due to its crucial role in facilitating N₂ adsorption and promoting the escape of photogenerated electrons. This review begins by examining the dual role of Mo in both biological and artificial photocatalytic nitrogen fixation. It systematically summarizes the application of various Mo-based photocatalytic materials in the field of nitrogen fixation, such as metal molybdates, molybdenum chalcogenides, and Mo-based MOFs/MXenes, along with modification strategies like Mo doping, Mo single atoms, and Mo metallenes. By elucidating the underlying mechanisms, the critical function of Mo in the nitrogen fixation process is highlighted. Finally, the challenges and future prospects of Mo-containing photocatalysts are discussed, providing a theoretical foundation for the development and selection of highly efficient Mo-containing materials for artificial nitrogen fixation.