Nanostructured nickel-iron-phosphorus alloy：electrosynthesis and application for hydrogen evolution reaction at neutral pH

Abstract

In this study nanostructured nickel-iron-phosphorus alloys (nanoNiFePx) were synthesized by electrochemical deposition and their applications as the electrocatalysts for the hydrogen evolution reaction (HER) were investigated The physicochemical properties of the prepared nanoNiFePx were characterized using scanning electron microscopy Raman spectroscopy inductively coupled plasma mass spectrometry and X-ray photoelectron spectroscopy linear sweep voltammetry cyclic voltammetry and chronopotentiometry It was found that deposition current density and composition of plating solution used for the electrosynthesis of nanoNiFePx had great influences on the surface morphology and chemical composition of the prepared nanoNiFePx For example electrodeposition with high deposition current density (geq -2 mA cm-2) low Ni/Fe molar ratio (le 1) or phosphorus-free content (0 M) resulted in the formation of NiFePx nanocubes whereas electrodeposition with low deposition current density low iron content or any amount of phosphorus favored the formation of NiFePx nanospheres In addition nanoNiFePx prepared with optimal synthetic conditions exhibited the best HER activity requiring overpotentials of 260 5±0 01 and 200 mV to achieve a current density of 10 mA cm-2 and turnover frequency of 37 29±5 81 h-1 at neutral pH respectively

Date of Award	2020
Original language	English
Supervisor	Chia-Yu Lin (Supervisor)