Synergistic effect of TiO2 nanostructured cathode in microbial fuel cell for bioelectricity enhancement

Abstract

Nano-bedecking of electrode with nanoparticles is an effective method to improve power generation of microbial fuel cells (MFCs). In this study, different concentrations (0.25 mg cm−2, 0.50 mg cm−2, 0.75 mg cm−2 and 1.0 mg cm−2) of TiO2 nanoparticles of size 10–25 nm were overlaid on the carbon cloth (CC) using spray pyrolysis technique and used as catalytic cathode in a dual-chambered microbial fuel cell treating distillery wastewater. Results evidenced that TiO2 nanoparticles modified cathode increased the power generation and recorded a highest power and current density of 162.5 ± 2 mW m−2 and 1.4 ± 0.005 A m−2, respectively. Carbon cloth coated with 0.50 mg cm−2 TiO2 nanoparticles showed 2.8 and 7.3 times higher current and power density as compared to uncoated cathode. MFC operated at a hydraulic retention time (HRT) and organic loading rate (OLR) of 72 h and 59.2 g COD L−1 d−1 showed a maximum chemical oxygen demand (COD) removal of 72.3% which was 15.3% higher than the control MFC. Likewise, the coulombic efficiency of control and modified MFC was 33% and 44%, respectively. The maximum NO3−- N, NO2−- N and NH4+- N removal efficiency of 77.3%, 49.9% and 59.4% were observed for TiO2 nanoparticles modified electrode which was 19.3%, 11.4% and 10.5% higher than control. TiO2 modified cathode was effective in enhancing the bioelectricity generation in MFCs.