Three-dimensional Ni foam supported pristine graphene as a superior oxygen evolution electrode

摘要

Oxygen evolution reaction (OER) represents a major kinetic bottleneck for water splitting. Three-dimensional (3-D) Ni foam (NF) supported pristine few-layer graphene was utilized as an oxygen evolution electrode, showing an overpotential of 382 mV to achieve 10 mA cm(-2) and a Tafel slope of 44.9 my dec(-1), both of which are lower than those of pristine NF and graphene and among the lowest reported for carbon and even transition metal-based catalysts measured under the same conditions, and much higher steady-state current density and much less reduction of current density after CV cycling compared to NF and graphene, with negligible current loss after 10 h chronoamperometry and 350 CV cycles. Its high catalytic performance is possibly due to the Ni-promoted OH- adsorption on and uniform dispersion and charge redistribution of the robustly attached graphene. This study not only provides a novel strategy to significantly enhance the OER activity of pristine graphene and creates a high-performance 3-D and binder-free oxygen evolution electrode, but offers scientific insight into the promotion effect of metal supports on the OER activity of pristine graphene. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.