Li Yaguang, Wu Zhong-Shuai, Lu Pengfei, Wang Xiao, Liu Wei, Liu Zhibo, Ma Jingyuan, Ren Wencai, Jiang Zheng, Bao Xinhe
Dalian National Laboratory for Clean Energy Dalian Institute of Chemical Physics Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China.
Hebei Key Lab of Optic-electronic Information and Materials The College of Physics Science and Technology Hebei University Baoding 071002 China.
Adv Sci (Weinh). 2020 Jan 20;7(5):1903089. doi: 10.1002/advs.201903089. eCollection 2020 Mar.
Single-atom catalysts (SACs) are efficient for maximizing electrocatalytic activity, but have unsatisfactory activity for the oxygen evolution reaction (OER). Herein, the NaCl template synthesis of individual nickel (Ni) SACs is reported, bonded to oxygen sites on graphene-like carbon (denoted as Ni-O-G SACs) with superior activity and stability for OER. A variety of characterizations unveil that the Ni-O-G SACs present 3D porous framework constructed by ultrathin graphene sheets, single Ni atoms, coordinating nickel atoms to oxygen. Consequently, the catalysts are active and robust for OER with extremely low overpotential of 224 mV at current density of 10 mA cm, 42 mV dec Tafel slope, oxygen production turn over frequency of 1.44 S at 300 mV, and long-term durability without significant degradation for 50 h at exceptionally high current of 115 mA cm, outperforming the state-of-the-art OER SACs. A theoretical simulation further reveals that the bonding between single nickel and oxygen sites results in the extraordinary boosting of OER performance of Ni-O-G SACs. Therefore, this work opens numerous opportunities for creating unconventional SACs via metal-oxygen bonding.
单原子催化剂（SACs）在最大化电催化活性方面效率很高，但对析氧反应（OER）的活性却不尽人意。在此，报道了通过氯化钠模板合成单个镍（Ni）单原子催化剂，其与类石墨烯碳上的氧位点结合（表示为Ni-O-G SACs），对OER具有优异的活性和稳定性。各种表征表明，Ni-O-G SACs呈现出由超薄石墨烯片、单个镍原子、将镍原子与氧配位构建的三维多孔框架。因此，该催化剂对OER具有活性且稳定，在电流密度为10 mA cm时过电位极低，仅为224 mV，塔菲尔斜率为42 mV dec，在300 mV时析氧周转频率为1.44 S，并且在115 mA cm的极高电流下长期耐用50 h无明显降解，性能优于目前最先进的OER单原子催化剂。理论模拟进一步表明，单个镍与氧位点之间的键合导致Ni-O-G SACs的OER性能得到显著提升。因此，这项工作为通过金属-氧键合创造非常规单原子催化剂开辟了众多机会。
