A cobalt-borate nanosheet array: an efficient and durable non-noble-metal electrocatalyst for water oxidation at near neutral pH

As a durable catalyst electrode, a cobalt-borate nanosheet array on a Ti mesh shows high activity for water oxidation in 0.1 M K-Bi (pH: 9.2), achieving a geometrical catalytic current density of 10 mA cm⁻² at an overpotential of 469 mV.