Electrochemical water splitting involving two-half chemical cell reactions is a promising approach to generate hydrogen and oxygen. Although this method is sustainable, the sluggish kinetics of the oxygen evolution reaction (OER) occurring at the anode due to a high overpotential is an issue to be addressed. Recently, various chemical and structural engineering approaches have been explored to improve the efficiency of the OER by reducing the overpotential. Among them, incorporating noble metals into the electrodes by doping or creating heterojunctions is an appealing approach to develop efficient OER electrocatalysts. Based on this principle, herein, we synthesized a bismuth-oxide (Bi