Investigating the performance of CoFe₂O₄@TiO₂ nanomaterial as multifunctional cathode catalyst for simultaneous dye degradation and oxygen reduction in microbial desalination cell

Microbial desalination cell (MDC) is an emerging technology in which water is desalinated and energy is generated by the breakdown of organic compounds and catalyzed by microorganisms using the potential gradient created in the reactor. MDC efficacy is substantially influenced by the oxygen reduction reaction (ORR) occurring at the cathode, albeit potential hindrances include sluggish reaction rates and biofouling development. The present study involved synthesizing and utilizing CoFe₂O₄@TiO₂ nanocomposite as a multifunctional catalyst on a cathode surface for efficient ORR and dye removal. XPS, HRTEM, and XRD techniques were used to ascertain the NPs' morphology, surface properties, dimensions, and XRD patterns. Physicochemical investigation showed that the nanoparticles had a consistent distribution, a mean diameter of 18.11 nm, and a spherical shape. Researchers tested MDCs with nanoparticles (NPs). The highest power density was 4.56 W/m³, 50 % more than the MDC with a lower loading density. The desalination efficiency was found to be 60 % at 1.5 mg/cm² CoFe₂O₄@TiO₂, however, it was 80 and 81 % at 2.5 and 2.0 mg/cm² catalyst concentrations, respectively. The dye degradation efficiency of as high as 88 % was observed with CoFe₂O₄@TiO₂ nanocomposite cathode MDC. The findings show that CoFe₂O₄@TiO₂ nanocomposite might be an economically feasible ORR catalyst, improving MDC efficiency and cost.