Electroless-hydrothermal construction of nickel bridged nickel sulfide@mesoporous carbon nitride hybrids for highly efficient noble metal-free photocatalytic H2 production

Metallic Ni bridged NiS@mesoporous carbon nitride hybrids were for the first time fabricated through a one-pot electroless-assisted hydrothermal method. The intimate Ni bridge between the interface of mesoporous carbon nitride and NiS was confirmed by HRTEM and in-depth XPS analysis using an Ar+-cluster sputtering gun and a possible mechanism was put forward to elucidate the formation process of the unique structure. Without adding any noble metals as cocatalysts, the optimized catalyst 10% NiS/m-CN-160-12 showed a H2 evolution rate of 1419 μmol·g−1·h−1, which is about 34 and 14 fold higher than that of bare mesoporous carbon nitride and NiS, respectively. The dramatically enhanced photocatalytic performance was mainly ascribed to the synergistic effect of NiS cocatalyst loading and the formation of metallic Ni between the interface of mesoporous carbon nitride and NiS, which served as a charge-transfer bridge to facilitate the transfer and separation of photo-induced electron-hole pairs.