The 2D porous NiSe/g-C3N4 nanosheets towards enhanced photocatalytic H2 evolution and degradation via synergism of co-catalyst and surface protonation.

The 2D porous protonated NiSe/g-C 3 N 4 nanosheets are synthesized via a chemical-calcination-etching-acidification-hydrothermal method. The obtained 2D NiSe/g-C 3 N 4 nanosheets (NiSe/HCN-3) exhibit signally enhanced HER (∼1184.74 μmol g−1 h−1)/degradation (∼0.04645 min−1) than the monomer g-C 3 N 4 (∼150/5-folds), including a decent stability (average HER ∼1152.71 μmol g−1 h−1). It mainly attributes to the NiSe/g-C 3 N 4 interface owns appropriate potential gradient can promote the interface carrier driving to optimize efficiency, including increasing carrier transport, extending carrier lifetime, and reducing recombination, as well as the porous nanosheets and surface protonation obtain numerous active sites for decreasing overpotential and promoting electron solid/liquid interfacial diffusion. Additionally, the 2D porous nanosheets can improve the solar efficiency (multiple internal reflections) and shorten the carrier pathway. [Display omitted] • NiSe co-catalyst optimize carrier efficiency by appropriate Fermi level gradient. • Surface protonation increase active sites to promote electron interfacial diffusion. • Porous nanosheets increase active sites/solar efficiency and shorten carrier path. [ABSTRACT FROM AUTHOR]