Porous honeycomb-like NiSe2/red phosphorus heteroarchitectures for photocatalytic hydrogen production
Heterojunction construction of semiconductors with matched bandgap can not only promote visible light absorption but also restrain photoexcited charge carrier recombination and optimize the separation efficiency. Herein, a novel porous honeycomb-like NiSe2/RP heterostructure was reported for the first time by in-situ deposition of NiSe2 nanoparticle on the surface of red phosphorus (RP). The optimized binary NiSe2/RP composite manifested superior photocatalytic H2 evolution activity (1968.8 μmol∙g-1∙h-1) from water with Na2S/Na2SO3 under solar light illumination, which was 2.32, 1.90, 1.59 and 1.21 times than that of pristine RP, NiSe2, 5.3% FeS/RP and 8.1% NiS/RP, respectively. The formation process and function of various reactive oxygen species (∙OH, ∙O2- and H2O2), and the migration pathway of photocarrier were discussed in detail. Such prominently improved photocatalytic performance could be ascribed to extending light absorption ability, massive reactive centers and lower interfacial transfer resistance, together with expediting charge separation arose from a successive two-electron/two-step reduction route. This study provides illuminating insights for the rational exploration and fabrication of potentially photocatalytic systems with 0D/3D integrated nanoarchitecture and multi-step electron transfer process for efficiently realizing solar energy capture and conversion.