Electrodeposition of NiS/Ni_2P nanoparticles embedded in amorphous Ni(OH)_2 nanosheets as an efficient and durable dual-functional electrocatalyst for overall water splitting

摘要

To develop earth-abundant and cost-effective catalysts for overall water splitting is still a major challenge. Herein, a unique "raisins-on-bread" Ni-S-P electrocatalyst with NiS and Ni2P nanoparticles embedded in amorphous Ni(OH)(2) nanosheets is fabricated on Ni foam by a facile and controllable electrodeposition approach. It only requires an overpotential of 120 mV for HER and 219 mV for OER to reach the current density of 10 mA cm(-2) in 1 M KOH solution. Employed as the anode and cathode, it demonstrates extraordinary electrocatalytic overall water splitting activity (cell voltage of only 1.58 V @ 10 mA cm(-2)) and ultra-stability (160 h @ 10 mA cm(-2) or 120 h @50 mA cm(-2)) in alkaline media. The synergetic electronic interactions, enhanced mass and charge transfers at the heterointerfaces facilitate HER and OER processes. Combined with a silicon PV cell, this Ni-S-P bifunctional catalyst also exhibits highly efficient solar-driven water splitting with a solar-to-hydrogen conversion efficiency of 12.5%. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.