Preparation of new ferroelectric Li0.95Ta0.57Nb0.38Cu0.15O3 materials as photocatalysts in microbial fuel cells

• Published in: Canadian journal of chemical engineering 2018-08, Vol.96 (8), p.1656-1662
• Main Authors: Louki, Sami, Touach, Nour‐eddine, Benzaouak, Abdellah, Salar‐García, María José, Ortiz‐Martínez, Víctor Manuel, Hernández‐Fernández, Francisco José, de los Ríos, Antonia Pérez, El Mahi, Mohammed, Lotfi, El Mostapha
• Format: Article
• Language: English
• Subjects: Biochemical fuel cells; Bioelectricity; Catalytic activity; Cathodes; Cooling; Electric power generation; Electrode materials; Ferroelectric materials; Ferroelectricity; Heat treatment; Maximum power density; microbial fuel cell; Microorganisms; Particle size distribution; Phases; Photocatalysis; photocatalyst; Photocathodes; rapid cooling; slow cooling; Synthesis; tantalo‐niobate phase; Wastewater treatment; Water treatment; X-ray diffraction
• ISSN: 0008-4034; 1939-019X
• DOI: 10.1002/cjce.23117

A microbial fuel cell (MFC) is a device for both the generation of bioelectricity and the treatment of wastewater. However, its performance is affected by several parameters, and more particularly the materials used as the active phase at the cathode. In order to develop new, more efficient cathodes, two new non‐stoichiometric ferroelectric cathode materials are studied in this work. These electrodes have been synthesized according to two heat treatment modes (slow cooling and rapid cooling) from non‐stoichiometric ferroelectric materials with the formula Li0.95Ta0.57Nb0.38Cu0.15O3. The synthesized phases were characterized by X‐ray diffraction (XRD), transmission electronic microscopy (TEM), particle size distribution (PSD), and differential scanning calorimetry (DSC). The main characteristics of these phases are the Curie temperatures, 1217 and 1197 °C, and the specific surfaces of 0.572 and 0.801 m2/g for the slow and rapid cooling phases, respectively. These materials were subsequently tested as photocathodes in a single chamber MFC in terms of the bioenergy production and wastewater treatment, by measuring the output power density and the rate of removal of COD in the presence of a light source. For the samples prepared by slow and rapid cooling, the values of maximum power density were 20.10 and 205.35 mW/m3, respectively. The COD removal rates were 74 and 80 %, respectively. Accordingly, the phase prepared by rapid cooling was shown to be more efficient in terms of power generation and wastewater treatment with a significant improvement in photocatalytic activity.