Electrooxidation of 5-hydroxymethylfurfural and electroreduction of nitrobenzene by hollow CoFeP cubes/rGO/Ni foam

Electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylate (FDCA) has attracted great attention due to its potential for producing degradable plastics. But, HMF electrooxidation still faces challenges such as high overpotentials and sluggish kinetics. Meanwhile, H2 evolution at the cathode is less cost-effective than cathodic reactions producing valuable chemicals. In view of this, a MOF-derived CoFeP cube anchored on rGO-encapsulated nickel foam (NF) via a facile wet-chemical method is reported. The CoFeP–rGO catalyst delivers a low potential of 1.38 V at a current density of 100 mA cm−2 in 1 M KOH containing 10 mM HMF, achieving ∼100% conversion, a 96% yield of FDCA, and 100% Faraday efficiency (FE). It acts as a bifunctional catalyst, demonstrating electrocatalytic reduction of nitrobenzene (NB) at low overpotential with 91% conversion. In the proposed mechanism, the CoFeP–rGO interface is proved to play a crucial role in increasing the catalytic activity via promoting dispersion of the CoFeP nanocrystals on the substrate and accelerating the electron transfer rate across the interface.