Self-Healing Graphene-Templated Platinum-Nickel Oxide Heterostructures for Overall Water Splitting.

Abstract

Electrocatalysts with dramatically enhanced water splitting efficiency, derived from controlled structures, phase transitions, functional activation, <i>etc.</i>, have been developed recently. Herein, we report an <i>in situ</i> observation of graphene-based self-healing, in which this functional activation is induced by a redox reaction. Specifically, graphene on stainless steel (SUS) switches between graphene (C-C) and graphene oxide (C-O) coordination via an electrical redox reaction to activate water splitting. A heterostructure comprising Pt-NiO thin films on single-layer graphene directly grown on a SUS substrate (Pt-NiO/Gr-SUS) was also synthesized by electrodeposition. Pt-NiO/Gr-SUS exhibited water splitting activity with low Pt loading (<1 wt %). The findings provide valuable insight for designing robust electrodes based on reversible redox-induced self-healable graphene to develop more efficient catalysts.