Bioenergy Generation and Wastewater Purification with Li[sub.0.95]Ta[sub.0.76]Nb[sub.0.19]Mg[sub.0.15]O[sub.3] as New Air-Photocathode for MFCs

MFC is a promising technology that can be used for simultaneous electricity generation and wastewater treatment. Power energy generation of a ferroelectric cathodic ceramic, Li[sub.0.95]Ta[sub.0.76]Nb[sub.0.19]Mg[sub.0.15]O[sub.3] (LTNMg), has been measured in microbial fuel cells, integrating a single chamber fed by industrial wastewater (COD[sub.initial] = 471 mg L[sup.−1], and pH[sub.initial] = 7.24 at T = 27 °C). In this process, the mixed multicomponent oxide material has been prepared and characterized by XRD, PSD, TEM, and UV-Vis spectroscopy. The catalytic activity has been investigated by COD determination, analysis of heavy metals, and polarization measurement. The results show a high COD reduction efficiency, which reaches 95.70% after a working time of 168 h with a maximal power density of 228 mW m[sup.−2]. In addition, the maximum value of generated voltage in the open-circuit potential (OCP) of this MFC configuration has been increased from 340 mV in the absence of a light source to 470 mV under irradiation, indicating the presence of a promoting photocatalytic effect of LTNMg, which improved the process of the cathodic electron transfer inside the MFC device.