College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, PR China.
Nanoscale. 2018 Oct 21;10(39):18767-18773. doi: 10.1039/c8nr05279d. Epub 2018 Oct 2.
The development and design of highly active and stable electrocatalysts based on cheap and Earth-abundant materials is critically important to enable water splitting as a desirable renewable energy source. Herein, we fulfill the significant electrochemical water splitting enhancement in both electrocatalytic activity and durability by constructing self-supported nickel-cobalt nanowire catalysts with abundant oxygen vacancies. Specifically, the rich oxygen vacancies can largely promote the oxygen evolution reaction (OER) activity of optimal NiCoO NWs with a relatively low overpotential of 248 mV to drive a current density of 10 mA cm. More significantly, after the phosphorization of NiCoO NWs, the resultant NiCoP NWs can also display excellent electrocatalytic hydrogen evolution reaction (HER) performances with an overpotential of only 101 mV to achieve a current density of 10 mA cm. Furthermore, benefiting from the unique 1D nanowire structure, the synergistic effect, and the optimal Gibbs free energy for hydrogen evolution evolved from the phosphorization, the NiCoO NWs//NiCoP NWs couple is thus highly active and stable for overall water electrolysis with a low voltage of 1.58 V at 10 mA cm, showing extraordinary promise for practical overall water splitting electrolysis.
基于廉价且丰富的材料开发高效稳定的电催化剂对于将水分解作为一种理想的可再生能源至关重要。在此，我们通过构建具有丰富氧空位的自支撑镍钴纳米线催化剂，在电催化活性和耐久性方面实现了显著的电化学水分解增强。具体而言，丰富的氧空位可以极大地促进最佳 NiCoO NWs 的析氧反应 (OER) 活性，使其在驱动 10 mA cm-2 的电流密度时具有相对较低的过电位 248 mV。更重要的是，NiCoO NWs 磷化后，所得的 NiCoP NWs 也可以表现出优异的析氢反应 (HER) 性能，过电位仅为 101 mV 即可实现 10 mA cm-2 的电流密度。此外，得益于独特的 1D 纳米线结构、协同效应以及磷化带来的最优析氢吉布斯自由能，NiCoO NWs//NiCoP NWs 偶联物在 10 mA cm-2 时的整体水分解具有低至 1.58 V 的低电压，表现出用于实际整体水分解电解的巨大应用潜力。
