Hierarchical zinc-nickel phosphides nanosheets on 3D nickel foam as self-support electrocatalysts for hydrogen evolution reaction

摘要

Developing high-effectiveness electrocatalysts towards hydrogen evolution reaction (HER) is important for the friendly generation of hydrogen gas on a large scale through electrochemical water splitting. In this study, a hybrid nanostructure based on zinc-nickel phosphide nanosheets vertically grown on a three-dimensional Ni foam (ZnNi-P NSs/NF) was prepared through an easy hydrothermal approach followed by a phosphidization process at 300 degrees C. The unique nanoarchitecture with hierarchical pores is advantageous for exposing satisfactory active sites and offering evaluable structure and electronic properties. Particularly, the addition of certain Zn-P amount significantly alters electronic structure of the ZnNi-P NSs hybrid, thereby leading to accelerate electrocatalytic activity for HER in 1.0 M KOH. In this context, the ZnNi-P NSs/NF displays requires small overpotentials of 175 and 291 mV to deliver current densities of 10 and 50 mA cm(-2), respectively, along with a small Tafel slope of 129 mV/dec, suppressing other synthesized materials and sufficiently reaching Pt/C catalyst. Furthermore, there is only minor reduction of current response and overpotential during continuous HER for over 1000 cycles, suggesting its impressive operation stability. The developed ZnNi-P NSs/NF with good catalytic activity and robust stability over the Pt/C catalyst can open a novel door for efficient water splitting technology. (C) 2019 Elsevier Ltd. All rights reserved.