B-modified phosphorene for N2 fixation: A highly efficient metal-free photocatalyst

Abstract The chemically inert N2 molecular can be converted into NH3 through the Haber–Bosch process at the expense of energy source and pollution. Exploring an efficient photocatalyst for N2 fixation is of great significance. Here, we theoretically designed a kind of B-modified phosphorene photocatalyst to achieve N2 fixation based on the first-principle calculations. The N2 molecules can be efficiently reduced into NH3 on the B/AC-phosphorene with the lower onset potential of 0.34 V, which makes the energy barrier reduce by 150% compared with the related previous report. Moreover, the N2 fixation mechanisms of B-modified phosphorene were explored. The B atom can act as transmitter to provide electron to N2 and make it activate. Meanwhile, the extension of light absorption spectrum, the increase of adsorption coefficient in the VIS and IR and the decrease of bandgap can make the phosphorene utilize sunlight efficiently to achieve N2 reduction. This study provides a novel way at the atomic level to explore highly efficient and environmentally friendly phosphorene based non-metal photocatalysts for N2 fixation in the experiments.