Charge kinetics evaluation of Fe3O4/V2O5 nanowires under visible light for energy conversion applications

In this study, surface-modified bundled V2O5 nanobelts with Fe3O4 nanoparticles were synthesized and their photoelectrochemical properties were recorded under illumination by light. The effects of the electrolyte on the heterostructured photoanode, structural and optical properties, as well as charge kinetic behavior of the photoelectrode were investigated. A combination of V2O5 and Fe3O4 nanostructures exhibited better light absorption than pristine V2O5 and Fe3O4 samples. With V2O5–Fe3O4, an electron-hole transfer resistance of 24.13 Ω and ion-path resistance of 109.8 Ω were achieved in a 0.1 M Na2SO3 electrolyte under irradiation. These values were lower than those obtained with pure V2O5 and Fe3O4 nanostructures. The photocurrent density of the V2O5–Fe3O4 photoanode considerably increased in Na2SO3 electrolytes compared to those of the others due to greater active sites in the photoanode and considerable improvements in the charge transfer resistance, limiting current density, and Tafel slope. Thus, V2O5–Fe3O4 photoanodes were established to be durable and stable materials for photoelectrochemical water splitting.