Co₃O₄/g-C₃N₄ nanocomposite for enriched electrochemical water splitting

Abstract

Designing an ideal bi-functional electrocatalyst for the overall water splitting plays significant function in alternative energy construction. Based on the previous literatures, the Co3O4/g-C3N4 nanocomposite has been investigated as the bi-functional electrocatalyst. In the present study, the facile hydrothermal route was approached to synthesize the Co3O4/g-C3N4 nanocomposite to enhance the electrocatalytic activity towards oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Further, Co3O4/g-C3N4 electrochemical analysis was undergone in an aqueous alkaline solution of 1 M potassium hydroxide for both OER and HER. High electrocatalytic nature of prepared Co3O4/g-C3N4 nanocomposite delivered the low 170 mV overpotential value and 151 mV at 20 mA/cm2 with Tafel values 188 mV/dec and 176 mV/dec for OER and HER. Also electrochemical surface area (ECSA) of prepared Co3O4/g-C3N4 nanocomposite was estimated from double layer capacitance (Cdl) values, and calculated ECSA values are 0.027 cm2 and 0.097 cm2 for OER and HER respectively. The resultant Co3O4/g-C3N4 nanocomposite reached the low charge transfer resistance value of 15.9 Ω for OER and 22.7 Ω for HER which could acts as strong parameter to improve conductivity of the prepared electrode for both half reactions. Along with that, stability of Co3O4/g-C3N4 nanocomposite exhibits the outstanding performance at the current density of 10 mA/cm2 with only minimum amount of loss even after 16 h for both OER and HER. Hence, the synthesized Co3O4/g-C3N4 nanocomposite was act as an optimistic choice of the bi-functional electro catalyst for sustainable energy production.