Construction of network-like and flower-like 2H-MoSe2 nanostructures coupled with porous g-C3N4 for noble-metal-free photocatalytic H2 evolution under visible light

Colloidally synthesized flower-like and network-like MoSe2 nanostructures are coupled with porous g-C3N4 nanosheets through a facile solution-phase route. Herein, two distinct morphological structures of MoSe2/g-C3N4 hybrid nanocomposites are applied as noble-metal-free photocatalysts for hydrogen (H-2) evolution. In the resulting optimally-designed hybrid systems, the optimal flower-like and network-like MoSe2 nanostructures loading is determined to be 5 wto/o, attaining a maximum H-2 evolution rate of 114.5 mu mol h(-1) g(-1) and 136.8 mu mol h(-1) g(-1), respectively. In comparison with flower-like MoSe2 cocatalysts, the network-like MoSe2 hybridized with g-C3N4 endows excellent photocatalytic H-2 evolution activity. This phenomenon stems from the intimate formation of unique sheet-on-sheet nanoarchitecture, which is auspicious for the absorption of light and high-efficiency separation of photoexcited electron-hole pairs to hamper the charge recombination. The present studies elucidate the prevailing role of MoSe2 nanostructures as active catalytic sites for H-2 evolution, and importantly, the hybrid systems exhibit high photocatalytic stability. Collectively, the work opens up new insights for the utilization of low-cost MoSe2 naoomaterials as remarkable noble-metal-free cocatalysts for effective photocatalytic H-2 generation.