Reaction environment self-modification on low-coordination Ni2+ octahedra atomic interface for superior electrocatalytic overall water splitting
atomic interface effect, overall water splitting, high current density, reaction environment self-modification, density functional theory
Large scale synthesis of high-efficiency bifunctional electrocatalyst based on cost-effective and earth-abundant transition metal for overall water splitting in the alkaline environment is indispensable for renewable energy conversion. In this regard, meticulous design of active sites and probing their catalytic mechanism on both cathode and anode with different reaction environment at molecularscale are vitally necessary. Herein, a coordination environment inheriting strategy is presented for designing low-coordination Ni2+ octahedra (L-Ni-8) atomic interface at a high concentration (4.6 at.%). Advanced spectroscopic techniques and theoretical calculations reveal that the self-matching electron delocalization and localization state at L-Ni-8 atomic interface enable an ideal reaction environment at both cathode and anode. To improve the efficiency of using the self-modification reaction environment at L-Ni-8, all of the structural features, including high atom economy, mass transfer, and electron transfer, are integrated together from atomic-scale to macro-scale. At high current density of 500 mA/cm2, the samples synthesized at gram-scale can deliver low hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) overpotentials of 262 and 348 mV, respectively.
Tsinghua University Press
Kaian Sun,Lei Zhao,Lingyou Zeng,Shoujie Liu,Houyu Zhu,Yanpeng Li,Zheng Chen,Zewen Zhuang,Zhaoling Li,Zhi Liu,Dongwei Cao,Jinchong Zhao,Yunqi Liu,Yuan Pan,Chen Chen, Reaction environment self-modification on low-coordination Ni2+ octahedra atomic interface for superior electrocatalytic overall water splitting. NanoRes.2020, 13(11): 3068–3074