g-C3N4 with a sustainable biomass-derived zinc vanadate hybrid supported on an industrial polyurethane sponge for methanol oxidation fuel cells and integrated with ML prediction models

Abstract

The efficacy of the methanol oxidation reaction is a primary prerequisite for an electrocatalyst in a direct methanol fuel cell (DMFC), which is influenced by the catalyst material and its synthesis technique. This study presents a novel electrocatalyst, specifically zinc vanadate (ZnV), graphitic nitride (CN), and the ZnV/CN nanohybrid, which were synthesized using a hydrothermal technique. This material serves as an anode on a polyurethane sponge sheet as the supporting substrate. The physical and chemical properties of the electrocatalyst were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and chronoamperometry (CA). SEM results indicate that the ZnV/CN nanohybrid-based electrocatalyst has a 3D structure with an exfoliated petal-like morphology resembling a cotton flower, thereby enhancing the active area of the electrocatalyst and facilitating better ion mobility. Furthermore, the highly developed porosity structure offers less resistance and a smooth conduit for protons to access the cathode. The results indicate that the current densities achieved with ZnV, CN, and the ZnV/CN nanohybrid/polyurethane as support layers are 45.4 mA cm−2, 75.38 mA cm−2, and 86.11 mA cm−2, respectively. The findings of this work are expected to be employed in catalyst design for a wide range of energy conversion devices.