Synthesis of Novel Schiff Base Cobalt (II) and Iron (III) Complexes as Cathode Catalysts for Microbial Fuel Cell Applications

A novel phosphate with CoII square planar coordination, BaCo0.5Fe(PO4)2: structural and magnetic features

A novel phosphate containing barium, cobalt, and iron was synthesized in single-crystal and polycrystalline forms. Single crystal-based X-ray measurements revealed that it crystallizes in the monoclinic system with the P21/c space group. The structure is made up of linkages between FeO6 octahedra, CoO4 square planar units, CoO5 square pyramidal units, and PO4 tetrahedra through edges and/or vertices. The interconnection of these polyhedra leads to a three-dimensional framework with tunnels along the a-axis where the Ba2+ cations are located. The polycrystalline form was prepared via the sol-gel method and its XRD pattern was refined by the Le Bail method. Morphological and elemental mapping analyses of this phosphate were performed by scanning electron microscopy. In addition, infrared and Raman spectroscopy provided more insights into chemical bonding. The magnetic behavior was antiferromagnetic below TN ∼ 20 K. Optical measurements revealed a direct bandgap with an energy Eg of 2.83 eV.

Decolorization mechanisms of reactive yellow 145 and ponceau S in microbial fuel cells during simultaneous electricity production

Environmental pollution is increasing in parallel with the increase in the world population. Azo dyes are one of the most important causes of environmental pollution. Microbial electrochemical cells are biotechnological systems that generate energy from renewable sources such as electricity. This study investigated simultaneous electricity generation with the decolorization of two different azo dyes in microbial fuel cells. And also, changes in pH values, chemical oxygen demand analysis, hourly color removal rate, dye spectral scanning were investigated. Reactive Yellow 145 dye with a concentration of 10 mg/L, 20 mg/L, and 40 mg/L, and Ponceau S dye with 20 mg/L and 40 mg/L concentration were tested in microbial fuel cells, respectively. Results indicate that the maximum voltage obtained was 0.11 V at the same time as the 100% decolorization rate in Reactive Yellow 145 and was achieved at a concentration of 10 mg/L also, the maximum voltage obtained was 0.24 V at the same time as the 100% decolorization rate in Ponceau S. It was achieved at a concentration of 20 mg/L. In conclusion, microbial fuel cells appear to be promising tools in treating textile azo dye wastewaters, and computational methods can be applied to estimate the degradation mechanisms of complex organic molecules found in wastewaters.