Enhanced cathode performance of a rGO–V2O5 nanocomposite catalyst for microbial fuel cell applications
A reduced graphene oxide–V2O5 nanocomposite was synthesized by a low temperature surfactant free hydrothermal method and its MFC performance was assessed. The structural properties of the synthesized nanocomposite were studied by X-ray diffraction. Field emission scanning electron microscopy of the nanocomposite revealed a wrinkled paper-like structure of rGO and a nanobelt-like structure of V2O5. This study estimated the viability of the graphene-based nanocomposite rGO–V2O5 as a novel cathode catalyst in single chamber air-cathode MFCs. A series of MFCs with different catalyst loadings were produced. The electrochemical behavior of the MFCs was calculated by cyclic voltammetry. The MFCs with the rGO–V2O5 nanocomposite cathode exhibited superior maximum power densities (83%) to those with the pure V2O5 cathodes. The rGO–V2O5 with a double-loaded nanocomposite catalyst achieved an enhanced power density of 1668 ± 11 mW m−2 and an OCP of 698 ± 4 mV, which was 83% of that estimated for the Pt/C 2004 ± 15 mW m−2 nanocomposite cathode. The significant increase in power density suggests that the reduced graphene oxide–V2O5 nanocomposite is a promising material for MFC applications. The CV result showed good agreement with the MFC result. The prepared rGO–V2O5 nanocomposite cathode, particularly with a double loading catalyst, is promising as a sustainable low-cost green material for stable power generation and long-term operation of MFCs.