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

Abstract

Microbial fuel cells (MFCs) provide new opportunities for the sustainable production of energy, converting organic matter into electricity through microorganisms. Moreover, MFCs play an important 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 non-precious photocatalysts for MFC cathode construction. Nanoparticles of BaTiO3 (BT) were prepared and tested in a microbial fuel cell (MFC) as photocathode catalytic components. The catalyst phases were synthesized, identified and characterized by XRD, SEM, UV–Vis absorption spectroscopy, P-E hysteresis and dielectric measurements. The maximum absorption of BT nanoparticles was recorded at 285 nm and the energy gap (Eg) was estimated to be 3.77 eV. Photocatalytic performance of cathodes coated with BaTiO3 was measured in a dark environment and then in the presence of a UV–visible (UV–Vis) light source, using a mixture of dairy industry and domestic wastewater as a feedstock for the MFCs. The performance of the BT cathodic component is strongly dependent on the presence of UV–Vis irradiation. The BT-based cathode functioning under UV–visible light improves the maximum power densities and the open circuit voltage (OCV) of the MFC system. The values increased from 64 mW m−2 to 498 mW m−2 and from 280 mV to 387 mV, respectively, showing that the 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 load in wastewater by 90% (initial COD = 2500 mg L−1).

Simultaneous removal of methylene blue and Cr(VI) in a dual-chamber photocatalytic microbial fuel cell with WO3/MoS2/FTO photocathode

“…In these coupled systems, the MFC provides a low voltage to reduce electron–hole complexation in the photocathode, thereby increasing pollutant removal efficiency [ 17 ]. Touach et al used BaTiO 3 functional chalcocite as a photocathode in a microbial fuel cell for wastewater treatment and energy production, which ultimately increased the maximum power density and open-circuit voltage of an MFC system [ 18 ]. Chen et al coupled Ce-g-C 3 N 4 photoelectrodes and a multistage microbial fuel cell for the treatment of highly concentrated saline amine-enriched industrial wastewater to remove 88 % of the chemical oxygen demand (COD) [ 19 ].…”

Theoretical Study on the Photoemission Performance of a Transmission Mode In0.15Ga0.85As Photocathode in the Near-Infrared Region

“…Photocathodes can emit photoelectrons due to the photoelectric effect, which has been extensively applied in electronic sources [ 1 ], photodetectors [ 2 ], photocatalytic fuel cells [ 3 ], and sensors [ 4 ]. Negative electron affinity (NEA) photocathodes exhibit super electron emission under light illumination owing to the fact that the photoelectrons can diffuse to the surface and reach vacuum level ( E v ) without extra energy, which leads to a high sensitivity [ 5 , 6 ].…”