Nickel‐Borate/Reduced Graphene Oxide Nanohybrid: A Robust and Efficient Electrocatalyst for Oxygen Evolution Reaction in Alkaline and Near Neutral Media.

Abstract: Designing highly active electrocatalysts with cost‐effective transition metals for oxygen evolution reaction (OER) is of vital significance for multifarious energy conversion and storage devices. Herein, a facile in situ co‐reduction method was applied for the preparation of nickel‐borate nanoparticle on reduced graphene oxide (Ni−B_i/RGO) with high surface active sites exposure yield and reinforced electron transfer ability. Such Ni−B_i/RGO nanohybrid shows high catalytic activity with overpotential of 329 mV to drive a geometrical current density of 10 mA cm⁻² and Tafel slop of 79 mV dec⁻¹ in 1  m KOH. Moreover, this Ni−B_i/RGO nanohybrid also displays excellent performance under near neutral condition, with a low onset potential of 352 mV and Tafel slop of 176 mV dec⁻¹ in 0.1  m potassium borate (KB_i, pH 9.2), better than most of Ni‐based OER catalysts. Our research has paved a facile path for the development of highly active electrocatalysts. [ABSTRACT FROM AUTHOR]