Abstract
Reduction of atmospheric dinitrogen (N(2)) to ammonia (NH(3)) using water and sunlight in the absence of sacrificial reducing reagents at room temperature is very challenging and is considered an eco-friendly approach to meet the rapidly increasing demand for nitrogen storage, fertilizers, and a sustainable society. Currently, ammonia production via the energy-intensive Haber-Bosch process causes ∼350 million tons of carbon dioxide (CO(2)) emission per year. Interestingly, natural N(2) fixation by the nitrogenase enzyme occurs under ambient conditions. Unfortunately, N(2) fixation on biomimetic catalysts has rarely been studied. To mimic biological nitrogen fixation, herein, we synthesized the novel iron molybdenum sulfide (FeMoS(x)) micro-/nanosheets via a simple hydrothermal approach for the first time. Further, we successfully demonstrated the photochemical conversion of N(2) to NH(3) over a biomimetic FeMoS(x) photocatalyst. The estimated yield is around 99.79 ± 6.0 μmol/h/g photocatalyst with a quantum efficiency of ∼0.028% at 532 nm visible-light wavelength. Besides, we also systematically studied the influence of key factors to further improve NH(3) yields. Overall, this study paves a new pathway to fabricate carbon-free, photochemical N(2) fixation materials for future applications.