Applied Surface Science, Vol.469, 61-67, 2019
CoxNiyP embedded in nitrogen-doped porous carbon on Ni foam for efficient hydrogen evolution
Here, a series of low-cost CoxNiyP nanoparticles embedded in N-doped porous carbon stood up on Ni foam nanocomposites (CoxNiyP@NC/NF) were prepared as efficient catalysts for hydrogen evolution reaction (HER) by a low temperature hydrothermal and phosphating method. Characterization of various techniques indicated the CoxNiyP nanoparticles with about 5 nm in diameter were uniformly embedded in NC to form CoxNiyP@NC nanosheets with thickness of 20-400 nm. The NC was composed of graphene and the CoxNiyP@NC nanosheets stood up on NF in crisscross fashion. The electrochemical results showed that the CoxNiyP@NC/NF nanocomposites showed high catalytic activity for HER in alkaline solution and its catalytic activity depended on the ratio of Co:Ni. At the ratio of Co:Ni of 4:1, the Co4NiP@NC/NF presented best HER performances with the overpotential of 70 mV at 10 mA cm(-1), better than commercialized Pt. The Co4NiP@NC/NF also displayed a wonderful Faraday efficiency of 95%, suggesting that it could effectively convert electrical energy into chemical energy in HER. The catalytic activity of Co4NiP@NC/NF remained unchanged in 35 h, indicating the Co4NiP@ NC/NF possessed good stability. The excellent HER performances might make it be a substitute for precious metal catalysts for hydrogen production.