Article BaTiO3 Functional Perovskite as Photocathode in Microbial Fuel Cells for Energy Production and Wastewater Treatment

: Microbial fuel cells (MFCs) provide new opportunities for the sustainable production ofenergy, converting organic matter into electricity through microorganisms. Moreover, MFCs play animportant role in remediation of environmental pollutants from wastewater with power generation.This work focuses on the evaluation of ferroelectric perovskite materials as a new class of nonprecious photocatalysts for MFC cathode construction. Nanoparticles of BaTiO3(BT) were preparedand tested in a microbial fuel cell (MFC) as photocathode catalytic components. The catalyst phaseswere synthesized, identified and characterized by XRD, SEM, UV-Vis absorption spectroscopy, P-Ehysteresis and dielectric measurements. The maximum absorption of BT nanoparticles was recordedat 285 nm and the energy gap (Eg) was estimated to be 3.77 eV. Photocatalytic performance ofcathodes coated with BaTiO3 was measured in a dark environment and then in the presence of aUV-visible (UV-Vis) light source, using a mixture of dairy industry and domestic wastewater as afeedstock for the MFCs. The performance of the BT cathodic component is strongly dependent on thepresence of UV-Vis irradiation. The BT-based cathode functioning under UV-visible light improvesthe maximum power densities and the open circuit voltage (OCV) of the MFC system. The valuesincreased from 64 mW m-2to 498 mW m-2 and from 280 mV to 387 mV, respectively, showing thatthe presence of light effectively improved the photocatalytic activity of this ceramic. Furthermore,the MFCs operating under optimal conditions were able to reduce the chemical oxygen demand loadin wastewater by 90% (initial COD = 2500 mg L-1).