Quasi-parallel nickel cobalt phosphide nanosheet arrays as highly efficient electrocatalyst for hydrogen evolution and overall water splitting at large current densities

• Published in: Journal of power sources Vol. 516; p. 230657
• Main Authors: Li, Lingfeng, Zou, Wenru, Ye, Qinglan, Li, Qi, Feng, Qishan, Wei, Jianrong, Xu, Xuetang, Wang, Fan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 31.12.2021
• Subjects: Hydrogen evolution reaction; Large-current-density; NiCo phosphide; Quasi-parallel nanosheet arrays; NiCo phosphide; Hydrogen evolution reaction; Quasi-parallel nanosheet arrays; Large-current-density
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2021.230657

Developing electrocatalysts with high activity for the hydrogen evolution reaction (HER) is a key prerequisite for overall water splitting. Herein, quasi-parallel NiCo phosphide (NiCoP) nanosheet arrays exhibiting a domain arrangement are grown onto Ni foam via a facile hydrothermal process followed by phosphorization. Benefiting from the strong interaction between Ni foam substrate and the as-loaded materials, quasi-parallel NiCo phosphide nanoarrays exhibit low resistance nature, high electrocatalytic activity and excellent stability toward HER in pH-universal electrolytes. Especially, it delivers the overpotential of 53 mV, 55 mV and 92 mV at 10 mA cm−2 in acidic, alkaline and neutral media, respectively. Impressively, the catalyst shows large current densities of 1000 mA cm−2 at low overpotentials, outperforming that of the commercial precious metal-based catalysts as well as the NiCoP nanosheet arrays with random alignment. Moreover, this novel and highly active catalyst enables a water splitting electrolyzer operating at the cell voltage of 1.49 V and 1.85 V to offer 10 mA cm−2 and 500 mA cm−2 in 1.0 M KOH at room temperature, together with high durability. [Display omitted] •Quasi-parallel NiCoP nanosheet arrays with domain pattern are grown on Ni foam.•Enhanced interaction between NiCoP nanosheet arrays and Ni substrate.•HER Overpotentials of 53 and 55 at 10 mA/cm2 in acidic and alkaline media.•Deliver 500 and 1000 mA/cm2 at 171 mV and 193 mV in KOH solution for HER.•1.49 V and 1.85 V to drive 10 and 500 mA/cm2 for overall water splitting.