Synthesis of Zn-Doped NiCoP Catalyst with Porous Double-layer Nanoarray Structure and Its Electrocatalytic Properties for Hydrogen Evolution

NiCoP is wildly accepted as one of the most potential catalysts for electrocatalytic hydrogen evolution reaction(HER)due to its high catalytic efficiency and low cost. However,the hydrogen bubble formation over catalyst surface during HER largely decreases the catalytic active sites and slows the mass transportation of electrolyte,resulting in a limited catalytic performance. In this paper,Zn-doped NiCoP catalyst with porous double-layer array structure on foam nickel was constructed by hydrothermal,followed with in. situ phosphating and HCl selective etching. Compared with the traditional single-layer array,the top nanoleaves array distributes uniformly on the bottom nanowires array,which maximizes the exposed catalytic active sites and provides a larger contact area for electrolyte. Moreover,the porous hierarchy also accelerates hydrogen bubble's release. As a result,the optimized H-Zn-NiCo-P shows high electrocatalytic activity in alkaline electrolyte (1 mol/L KOH),with overpotentials of 59 and 156 mV at the current densities of 10 and 100 mA/cm(2), respectively. The Tafel slope is 66 mV/dec and it shows excellent electrochemical stability. This research provides new ideas and solutions for the development of electrocatalysts with novel array structure.