Enhanced biohydrogen production from sugar industry effluent using nickel oxide and cobalt oxide as cathode nanocatalysts in microbial electrolysis cell

Abstract

SummaryDevelopment of economically viable cathode catalysts with practicability in the treatment of real effluents is one of the strenuous efforts among the multidisciplinary approaches in microbial electrolysis cell (MEC). Treatment of industrial effluents using this technology had resulted in simultaneous energy production in the form of hydrogen along with wastewater treatment, promoting both energy and environmental benefits. In this study, two metal oxides such as, Nickel Oxide (NiO) and Cobalt oxide (Co3O4) were employed as the cathode catalyst using sugar industry effluent as the substrate for biohydrogen production in the MEC. The addition of NiO and Co3O4 on nickel foam (NF) has demonstrated better hydrogen evolution performance than the control (uncoated) cathode. Electrochemical characterization of the modified cathodes revealed the improved capability analogous to the current density and hydrogen production rate (HPR) obtained in the experimentation. The best performance was achieved by NiO/NF with the maximum HPR of 3.39 ± 0.03 mmol/L/D, coloumbic efficiency of 58 ± 1.4%, hydrogen recovery of 27 ± 1.8% and COD removal efficiency of 52 ± 1.6% when operated with the applied voltage of 1.0 V. Hence, the potential of metal oxides was demonstrated for the candidature of efficient and economical cathode materials in MECs.