Novel 2D BSas a metal-free photocatalyst for water splitting.

Metal-free semiconductors with desirable characteristics have recently gained great attention in the field of hydrogen generation. The non-metal material BShas two phases, hexagonal BS(-BS) and orthorhombic BS(-BS), which compose a novel class of 2D materials. Both-BSand-BSmonolayers are direct semiconductors with bandgaps of 2.89 and 3.77 eV by the Heyd-Scuserria-Ernzerhof (HSE) function, respectively. Under appropriate uniaxial strain (1%), the bandgap of-BScan be decreased to 2.8 eV. The carrier mobility can reach 1160 cmVs, supporting the fast migration of photo-induced carriers. Most importantly, the band edges of both-BSand-BScover the reduction and oxidation levels for water splitting. We explore the process of photocatalytic water splitting on-BSmonolayers by analyzing the feasibility of the decomposition of HO and the generation of H. The results indicate that the special mesoporous structure of BSis helpful for photocatalytic hydrogen production. The new nanomaterial, BS, offers great promise as a metal-free photocatalyst due to its tunable bandgaps, its useful band edges, and its other excellent electronic properties.