Synthesis of Silver Nanocubes@Cobalt Ferrite/Graphitic Carbon Nitride for Electrochemical Water Splitting

Abstract

This study presents the synthesis of graphitic carbon nitride (g-C3N4) and its nanostructures with cobalt ferrite (CoFe2O4) and silver nanocubes (Ag) when using the combined pyrolysis of melamine and the polyol method. The resulted nanostructures were tested as electrocatalysts for hydrogen and oxygen evolution reactions in alkaline media. It was found that Ag@CoFe2O4/g-C3N4 showed the highest current density and gave the lowest overpotential of −259 mV for HER to reach a current density of 10 mA cm−2 in a 1 M KOH. The overpotentials for reaching the current density of 10 mA·cm−2 for OER were 370.2 mV and 382.7 mV for Ag@CoFe2O4/g-C3N4 and CoFe2O4/g-C3N4, respectively. The above results demonstrated that CoFe2O4/g-C3N4 and Ag@CoFe2O4/g-C3N4 materials could act as bifunctional catalysts due to their notable performances and high stabilities toward hydrogen and oxygen evolution reactions (HER and OER). Total water splitting in practical applications is a promising alternative to noble-metal-based electrocatalysts.