SiOC-based polymer derived-ceramic porous anodes for microbial fuel cells

Abstract

The applicability of a new class of ceramic materials in Microbial Fuel Cells (MFCs) was investigated, targeting the development of cost-effective anode materials with long-term durability. In this work, silicon oxycarbide (SiOC)-based porous anodes were prepared by the polymer-derived ceramics (PDCs) route, using poly(methyl silsesquioxane) and poly(methyl phenyl silsesquioxane) as precursors while incorporating carbonaceous fillers (graphite and carbon black) and metal precursor (NiCl2). Tape casting was used in the manufacturing followed by pyrolysis at 1000 °C under nitrogen atmosphere. The interior structure and surface morphology were characterized with scanning electron microscopy (SEM), nitrogen adsorption, vapor adsorption, and contact angle measurements. The developed anodes were tested in MFC with aqueous cathode configuration using a low-cost clayware cylinder as the anodic chamber. The performance of MFC using PDC-based anodes was compared with MFC having carbon felt as anode material, which showed a two-fold increase in power density (211 and 111 mW m−2, respectively) and normalized energy recovery in former and also demonstrated chemical oxygen demand (COD) removal efficiency of about 85%. The improved performance of the PDC-based anodes is attributed to its porous structure, hydrophilic surface, and high specific surface area (39.89 m² g−1). The biocompatibility was confirmed by biofilm growth on the surfaces, while a sufficient electrical conductivity (0.10–0.18 S cm−1) makes it superior electrode material for application in MFCs.