In-situ grown 3D-h-ZCO/NF as a bifunctional catalyst towards oxygen evolution reaction and electrocatalytic CO₂ reduction

Currently, mass production of oxygen with high energy generation (>500 mA cm⁻²) through oxygen evolution reaction (OER) in seawater is exceptionally desirable. Here, we extensively studied the binder-free and time-saving approach of synthesizing dual active electrocatalysts with low-cost, eco-friendly, and high energy density. In OER, the synthesized 3D-hierarchical-ZnCo₂O₄/NF (3D-h-ZCO/NF) achieved a high current density of 500 and 1000 mA cm⁻². Further, we extended the study towards an electrochemical carbon-dioxide reduction reaction (ECO₂RR) to investigate the bifunctional activity. It converts CO_2(g) into HCOO⁻ with excellent faradaic efficiency (FE) of 86.3 % ± 0.5 at −1.2 V vs. RHE. Further, the DFT studies support the enhanced catalytic and kinetic parameters of 3D-h-ZCO/NF by investigating the OERand ECO₂RR mechanisms. This study unveils the surface engineering approach of bare Ni-foam into a robust bifunctional electrocatalyst for seawater-splitting and ECO₂RR, dramatically impacting high efficiency and environmental remediation.