State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), 66 West Changjiang Road, Qingdao, Shandong 266580, China.
College of New Energy, China University of Petroleum (East China), 66 West Changjiang Road, Qingdao, Shandong 266580, China.
J Colloid Interface Sci. 2023 Sep;645:188-199. doi: 10.1016/j.jcis.2023.04.144. Epub 2023 May 3.
Manufacturing low-cost, high-performance and earth-rich catalysts for hydrogen evolution (HER) and oxygen evolution reactions (OER) is critical to achieving sustainable green hydrogen production. Herein, we utilize lacunary Keggin-structure [PWO] (PW) as a molecular pre-assembly platform to anchor Ni within a single PW molecule by vacancy-directed and nucleophile-induced effects for the uniform dispersion of Ni at the atomic level. The chemical coordination of Ni with PW can avoid the aggregation of Ni and favor the exposure of active sites. The NiS confined by WO prepared from controlled sulfidation of NiPW/Nickel Foam (NiPW/NF) exhibited excellent catalytic activity in both 0.5 M HSO and 1 M KOH solutions, which required only 86 mV and 107 mV overpotentials for HER at a current density of 10 mA∙cm and 370 mV for OER at 200 mA∙cm. This is attributed to the good dispersion of Ni at the atomic level induced by trivacant PW and the enhanced intrinsic activity by synergistic effect of Ni and W. Therefore, the construction of active phase from the atomic level is insightful to the rational design of dispersed and efficient electrolytic catalysts.
用于析氢反应（HER）和析氧反应（OER）的低成本、高性能和富含地球元素的催化剂的制备对于实现可持续的绿色氢气生产至关重要。在此，我们利用缺位导向和亲核诱导效应，将 lacunary Keggin 结构 [PWO]（PW）作为分子预组装平台，将 Ni 锚定在单个 PW 分子内，实现 Ni 在原子水平上的均匀分散。Ni 与 PW 的化学配位可以避免 Ni 的聚集并有利于活性位的暴露。通过 NiPW/Ni 泡沫（NiPW/NF）的可控硫化制备的 NiS 限域在 WO 中，在 0.5 M HSO 和 1 M KOH 溶液中均表现出优异的催化活性，在电流密度为 10 mA∙cm 时，HER 需要的过电位仅为 86 mV，在 200 mA∙cm 时，OER 需要的过电位仅为 370 mV。这归因于 PW 的三缺位诱导的 Ni 在原子水平上的良好分散以及 Ni 和 W 的协同效应增强的内在活性。因此，从原子水平构建活性相对于设计分散和高效的电解催化剂具有启发性。
