RuNiOx Interface Promotes Hydrogen Production from Alkaline Seawater

Abstract

Hydrogen production from seawater is increasingly important as an alternative technic for realizing low-cost and green energy without exacerbating CO2 emissions due to the abundant seawater in nature. However, practical application is still hindered by the electrochemical catalyst’ poor stability under rigorous industry conditions. Herein, nanoplate ruthenium-nickel oxide (RuNiOx) supported on nickel foam is fabricated for hydrogen production from alkaline seawater with eminent stability. Mechanism study shows the real active center is the in-situ formed ruthenium cluster with the supported NiO. The interface of cluster Ru with NiO results in reduced water-dissociated energy for the Volmer step. This robust electrode exhibits an overpotential of 16mV at 10 mA cm-2 with a small Tafel slope of 21.3mVdec-1. It can be operated under a large current density at 1000 mA cm-2 over 350 hours in alkaline freshwater. When paired with oxygen-produced catalyst S-NiFeOOH, this electrode can work at an industrial current density of 500 mA cm-2 for 100 hours and even 1A cm-2 over 30 hours in alkaline seawater. At industrial temperature (65 ℃), 12 hours of operation can be achieved. This work paves a feasible pathway for hydrogen production from seawater industry applications.