Partic. vol. 34 pp. 147-155 (October 2017)
doi: 10.1016/j.partic.2017.02.006

On the use of ferroelectric material LiNbO₃ as novel photocatalyst in wastewater-fed microbial fuel cells

N. Touach^{a, b, *}, V.M. Ortiz-Martínez^{b, *}, M.J. Salar-García^{b, *}, A. Benzaouak^a, F. Hernández-Fernández^b, A.P. de Ríos^c, M. El Mahi^a, E.M. Lotfi^{a, *}

noureddine.touach@um5s.net.mavictor.ortiz@upct.es

Abstract

In this work, the use of lithium niobate (LiNbO₃), a ferroelectric and photocatalyst material, is investigated as a new type of cathode catalyst for wastewater-fed single-chamber microbial fuel cells (MFCs). Carbon cloth electrodes coated with LiNbO₃ were studied with and without UV–vis irradiation to assess its photocatalytic behavior in these devices. The synthesized phase of LiNbO₃ was characterized by X-ray diffraction, differential scanning calorimetry, particle size distribution, and transmission electron microscopy analyses. The MFC containing a LiNbO₃-based cathode exhibited a maximum open circuit potential and power output of 400 mV and 131 mW/m³, respectively, under irradiation. This cathode configuration also achieved the maximum chemical oxygen demand removal of 84% after 120 h of MFC operation. These results show that ferroelectric materials such as LiNbO₃ could be used as cathode catalysts in MFC devices. As a complementary analysis, the removal of the heavy metals detected in the wastewater was also monitored.

Graphical abstract

Keywords

Lithium niobate; Ferroelectric material; Photocatalyst; Microbial fuel cell (MFC); Power output; Wastewater treatment