Three-dimensional iron–cobalt phosphide nanosheets on nickel oxide nanoparticles for improved glucose oxidation reaction†

The development of earth-abundant, highly active, and long-term durable electrocatalysts is crucial for advancing the practical applications of biofuel cells (BFCs). Herein, we demonstrate heterostructured three-dimensional (3D) iron-cobalt phosphide nanosheets on nickel oxide nanoparticles (3D FeCoP NS|NiO NP) for enhanced glucose oxidation reaction (GOR) under an alkaline electrolyte. The 3D FeCoP NS|NiO NP heterostructured electrodes are developed using a chemical etching approach followed by an electrochemical deposition strategy. The 3D FeCoP NS|NiO NP heterostructures deliver a higher catalytic anodic current density (∼10.34 mA cm⁻²) with a less positive potential (∼0.22 V (vs. Ag/AgCl)), greater mass activity (∼16.0 A g⁻¹), high double layer capacitance (∼0.88 mF cm⁻²), high electrochemically active surface area (ECSA) (∼22.12 cm⁻²), highest sensitivity (13.97 mA cm⁻²) and long-term durability (100 h). The 3D nanosheet-like surface morphology, less agglomerated structure, high ECSA, and synergistic effect of Fe and Co are responsible for the enhanced electrocatalytic GOR activity of the 3D FeCoP NS|NiO NP heterostructures. Addressing the cost-effectiveness of the 3D FeCoP NS|NiO NP heterostructures while maintaining high performance is necessary to make potential biofuel cells. Furthermore, ensuring the long-term stability of the 3D FeCoP NS|NiO NP heterostructures will guarantee reliable and sustained operation in real-world applications.