Fig. 1

Synthesis of Mo₂N and P–Mo₂N. a Schematic illustration of the synthesis of Mo₂N, two precursors in a are ethanediamine and MoO₃, respectively. b The surface model of Mo₂N, which is used for BP loading, that is, BP and Mo₂N are treated by vacuum stirring. c The surface model of BP-Mo₂N, the gray part is loaded BP. d The model of P doped Mo₂N lattice structure, the blue dots are P element in the lattice. e–g The corresponding TEM images of Mo₂N, BP-Mo₂N, and P–Mo–N, respectively. The scale bars are 50, 20, and 50 nm in e, f, and g, respectively. The white spots in TEM image of BP-Mo₂N is the BP, which disappears after the calcination treatment as shown in P–Mo–N image, suggesting the P doping into the lattice of Mo₂N