Electrochemical glucose oxidation reaction (GOR) is a promising alternative anodic reaction to water oxidation reaction for various electrochemical oxidation reactions owing to the relatively low thermodynamic potential of GOR and the abundant source of glucose from biomass-based platform molecules. However, it remains difficult to develop high-activity and low-cost electrocatalysts toward GOR. Herein, we report a NiCoSe x nanoplate supported on Ni foam with excellent activity for GOR electrocatalysis, which achieves a high current density of 500 mA cm −2 at 1.41 V vs reversible hydrogen electrode (RHE) and a 70.2% Faraday efficiency of formate at 1.40 V vs RHE. The surface component evolution of NiCoSe x is studied by an in situ Raman spectrum, which points out the catalytic active species to be CoO x /CoOOH and NiOOH. Furthermore, we develop a two-electrode cell by pairing GOR with hydrogen evolution reaction using the NiCoSe x electrode as the bifunctional catalyst for the anode and the cathode, which only requires an applied voltage of 1.50 V to reach a high current density of 200 mA cm −2 and retains long-term stability over 18 h with a high Faraday efficiency of H 2 (close to 100%) in the cathode.

The oxygen evolution reaction (OER) is critical for many clean energy conversion and storage technologies because it contributes the electrons required for converting renewable electricity into value-added chemicals. Electrocatalysts can promote the sluggish oxygen evolution process involving four-electron transfer. Herein, we prepare mesoporous spinel oxide nanosheets and develop an efficient strategy using Fe substitution to enable mesoporous NiCo2O4 nanosheets to generate superior active centers for the OER. Additionally, the iron substitution also promotes the preoxidation of Co/Ni and facilitates the formation of active species. Raman spectroscopy data reveal that the active species of mesoporous NiCo2O4 nanosheets for the OER is NiCo2O4 itself, and the active species of Fe substitution in NiCo2O4 nanosheets are Ni­(Co) oxyhydroxides. Therefore, the iron substitution is beneficial to facilitate the transformation of spinel NiCo2O4 into active Ni­(Co) oxyhydroxides under OER conditions. Owing to the mesoporous nanosheet structure and the formation of oxyhydroxide active species, the optimized mesoporous Fe0.2Ni0.8Co2O4 nanosheet catalyst exhibits a low overpotential of 270 mV to deliver a current density of 10 mA cm–2 and a small Tafel slope of 39 mV dec–1 for the oxygen evolution reaction in alkaline media.