Enhancing the performance of microbial fuel cells (MFCs) with nitrophenyl modified carbon nanotubes-based anodes.

Modification of carbon based-nanomaterials has been proven to be efficient for improving the MFCs performance, since the anode material significantly impacts the biofilm formation and the electron transfer between the microorganism and the electron acceptor. Surface treatment or functionalization is frequently employed to enhance the chemical reactivity and modify the hydrophobic surface of carbon nanotubes (CNTs). This work aims to explore the modification of CNTs with nitrophenyl groups for the improvement of the performance of MFC through anode modifications. Two procedures, involving 4-nitroaniline or 4-nitrobenzenediazonium tetrafluoroborate, were used for the chemical modification of CNTs. The X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and cyclic voltammetry were used for the characterizations of nitrophenyl modified CNTs. The maximum power density was obtained when 4-nitrobenzenediazonium tetrafluoroborate was used for the modification of the surface of CNTs. The introducing of nitrogen functionality on the anode surface and the control of the nitrogen content provide considerable encouragements for enhancing the MFCs performance through anode modifications. • CNTs surface was modified with nitrophenyl group via diazonium chemistry. • Nitrophenyl modified CNTs was used for the improvement of MFC performances. • Increase of nitrophenyl functionality on surface increased the power output of MFC. • Modification with tetrafluoroborate gives better coverage of nitrophenyl on surface. [ABSTRACT FROM AUTHOR]