Modified graphite electrodes as potential cathodic electrocatalysts for microbial electrolysis cells

Abstract

Microbial electrolysis cell (MEC) is an ecologically clean and innovative technology for hydrogen production. The development of cost-effective cathodes with high catalytic activity for hydrogen evolution reaction (HER) in nearneutral electrolytes is the most critical challenge for the practical application of MEC technology. In this study, graphite electrodes, functionalized with non-noble metal oxides, were produced and after electrochemical pre-treatment investigated as potential cathodes for MEC. The morphology of the developed materials was analyzed by scanning electron microscopy (SEM). Their electrochemical performance in neutral phosphate buffer solution (PBS) was explored by means of linear sweep voltammetry (LSV) and chronoamperometry (CA). The results from both methods show that all modified electrodes exhibit higher electrocatalytic activity towards HER than that of bare graphite, which is a prerequisite for further evaluation of these materials as cathodes in real MEC.

Validity and Reproducibility of Counter Electrodes for Linear Sweep Voltammetry Test in Microbial Electrolysis Cells

“…The catalyst with a steeper slope (m) is the more effective producer of hydrogen gas, allowing for a higher current under an applied voltage [67]. Therefore, to compare the reproducibility of each value, LSV curves were analyzed by linear regression to obtain the values of E f and m [68].…”

Industrial bioelectrochemistry for waste valorization: State of the art and challenges

“…An alternative environmentally-friendly technology for producing H 2 is the microbial electrolysis cell (MEC). While MFCs produce energy by organic matter oxidation, MEC requires an output source of energy to partially reverse the process to generate H 2 from organic matter (Chorbadzhiyska et al, 2011). H 2 is obtained at the cathode by the reduction of the protons produced by the degradation of organic matter at the anode (see Fig.…”