The application of bio-Pd(0) as a biogenic cathode in a microbial fuel cell

Abstract

The increasing concerns of climate change, energy generation, storage, consumption, and water pollution are topics that are gaining attention within modern research fields. This has led to numerous researchers devoting their efforts to developing green technologies that will alleviate these challenges with technologies that are energy efficient, cost-effective, and have low to no carbon dioxide emission. One of the most promising emerging technologies is the Microbial Fuel Cell (MFC) as bioelectricity generation and wastewater treatment is simultaneously achieved during microbial metabolism. However, MFCs are still incompatible with high energy demands due to practical limitations. The overall performance of an MFC depends on the microorganism, appropriate electrode materials, and suitable MFC designs. This work aims to improve the performance of an air-cathode MFC by optimizing the cathode electrode through the introduction of bio-Pd(0) as a catalyst. A consortium of Sulfate-Reducing Bacteria (SRB) isolated from a wastewater treatment plant and Pd(II) was used to fabricate the bio-Pd(0) catalyst through the reduction of Pd(II) by the consortium. The catalyst was characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) which revealed the presence of Pd(0) deposits on the cell surface of the bacteria. Following fabrication, the bio-Pd(0) catalyst was introduced to the cathode, and the MFC recorded a maximum power density of 0.044 mW m-3 and a peak voltage of 215.5 mV.