Construction of FeCo₂O₄@N-Doped Carbon Dots Nanoflowers as Binder Free Electrode for Reduction and Oxidation of Water

Abstract

Electrochemical water splitting is known as a potential approach for sustainable energy conversion; it produces H2 fuel by utilizing transition metal-based catalysts. We report a facile synthesis of FeCo2O4@carbon dots (CDs) nanoflowers supported on nickel foam through a hydrothermal technique in the absence of organic solvents and an inert environment. The synthesized material with a judicious choice of CDs shows superior performance in hydrogen and oxygen evolution reactions (HER and OER) compared to the FeCo2O4 electrode alone in alkaline media. For HER, the overpotential of 205 mV was able to produce current densities of up to 10 mA cm−2, whereas an overpotential of 393 mV was needed to obtain a current density of up to 50 mA cm−2 for OER. The synergistic effect between CDs and FeCo2O4 accounts for the excellent electrocatalytic activity, since CDs offer exposed active sites and subsequently promote the electrochemical reaction by enhancing the electron transfer processes. Hence, this procedure offers an effective approach for constructing metal oxide-integrated CDs as a catalytic support system to improve the performance of electrochemical water splitting.

Keywords

• water splitting
• carbon dots
• iron-cobalt oxide
• hydrogen evolution reaction
• oxygen evolution reaction