TY  - JOUR
AU  - Li, Cong
AU  - Xue, Jiang-Yan
AU  - Zhang, Wei
AU  - Li, Fei-Long
AU  - Gu, Hongwei
AU  - Braunstein, Pierre
AU  - Lang, Jian-Ping
PY  - 2023
TI  - Accelerating water dissociation at carbon supported nanoscale Ni/NiO heterojunction electrocatalysts for high-efficiency alkaline hydrogen evolution
JO  - Nano Research
SN  - 1998-0124
SP  - 4742
EP  - 4750
VL  - 16
IS  - 4
AB  - The synergistic catalysis of heterojunction electrocatalysts for the multi-step process in hydrogen evolution reaction (HER) is a promising approach to enhance the kinetics of alkaline HER. Herein, we proposed a strategy to form nanoscale Ni/NiO heterojunction porous graphitic carbon composites (Ni/NiO-PGC) by reduction-pyrolysis of the preformed Ni-metal-organic framework (MOF) under H2/N2 atmosphere. Benefiting from low electron transfer resistance, increased number of active sites, and unique hierarchical micro-mesoporous structure, the optimized Ni/NiO-PGC10-1-400 exhibited excellent electrocatalytic performance and robust stability for alkaline HER (η10 = 30 mV, 65 h). Density functional theory (DFT) studies revealed that the redistribution of electrons at the Ni/NiO interface enables the NiO phase to easily initiate the dissociation of alkaline H2O, and shifts down the d-band center of Ni and optimizes the H* adsorption–desorption process of Ni, thereby leading to extremely high HER activity. This work contributes to a further understanding of the synergistic promotion of the multi-step HER processes by heterojunction electrocatalysts.
UR  - https://doi.org/10.1007/s12274-022-5194-5
DO  - 10.1007/s12274-022-5194-5