Hollow and Ultrathin Mo-Doped CoP Bamboo-Leaf Nanoarrays for pH-Universal Hydrogen Evolution

The rational design of cost-effective electrocatalysts for the hydrogen evolution reaction (HER) still remains a major challenge in continuable energy storage and conversion systems. In this study, vertically hollow and ultrathin Mo-doped CoP (Mo-CoP) nanoarrays are prepared on nickel foam by hydrothermal and low-temperature phosphating strategies. The Mo-CoP nanoarrays possess a bamboo-leaf structure with the diameter ranging from 20 to 150 nm between the top and the bottom and the length of several microns. At the same time, the Mo-CoP substance presents a crystalline–amorphous structure. The synergistic effect of doping and special construction can supply plentiful active sites, enhance electrolyte penetration, and facilitate gas diffusion in the process of the electrocatalytic reaction. The overpotentials of the Mo-CoP electrode at 10 mA cm–2 are as low as 88.4, 78.7, and 112.6 mV, and the Tafel slopes are 87.2, 55.7, and 120.3 mV dec–1 in alkaline, acidic, and neutral electrolytes, respectively. Moreover, the Mo-CoP catalyst also displays a favorable long-term stability in all pH ranges.