The synergistic effect of Co3O4 and KNbO3 in Co3O4@KNbO3 composite for enhanced performance of water oxidation

A novel Co3O4@KNbO3 composite composed by Co3O4 and KNbO3 was synthesized via a two-step process combining the sol–gel method with calcination. Impressively, the obtained Co3O4@KNbO3 can be used as an efficient OER electrocatalyst with an overpotential of 330 mV at 10 mA·cm−2, a low Tafel slope of 61 mV·dec-1, and a negligible increase of the overpotential after the 3,000 cycle stability test. The excellent performance for OER was ascribed to the abundant electrochemical active sites and synergistic effect between Co3O4 and KNbO3.