The Research Of Gallium Oxides Modified Activated Carbon Air Cathode Applied In Microbial Fuel Cell

Energy shortage and environmental pollution problem are more serious with the development of economy.The development and utilization of new energy caused widely attention.Microbial fuel cells which use the organic pollutants as electron donor combine energy generation and sewage treatment technology.Using activated carbon as MFCs air cathode material is the most widely used,but the application was limited due to its low capacity.Therefore,research on modification of traditional activated carbon has caused more and more attention.At present,in order to improve the conductivity of MFCs most of the studies focused on the modification of traditional activated carbon with transition metals.In this study,the non transition metal-semiconductor modified activated carbon was used as MFCs air cathode catalyst,to improve the power density.Meanwhile,the electrochemical properties and oxidation reduction mechanism in this equipment were analyzed.Nanorod monoclinic?-Ga₂O₃ semiconductor,prepared via a facile hydrothermal method was used as catalyst to modify activated carbon air-cathode microbial fuel cell?MFC?.The maximum power density of the modified MFC was 1843±40 mW m^-2,3 times as high as the control.Brunauer-Emmett-Teller?BET?,transmission electron microscope?TEM?and X-ray diffraction?XRD?results revealed the larger surface area and porous structure which could provide more active sites to improve the performance of MFC.The result of X-ray photoelectron spectroscopy?XPS?confirmed that the high rate oxygen vacancy existed in the?-Ga₂O₃.Tafel curve and Rotating disk electrode?RDE?results illustrated the high exchange current density of?-Ga₂O₃ and the four-electron pathway at the cathode during the oxygen reduction reaction?ORR?.The?-Ga₂O₃ modified cathode demonstrated excellent improvement towards the ORR and then improved the performance of MFC.Nano spinel bulk-like CoGa₂O₄ prepared via a facile hydrothermal method was modified activated carbon?AC?air-cathode microbial fuel cell?MFC?.The maximum power density was 1911±49 mW m^-2,147%higher than the control.Transmission electron microscope?TEM?and X-ray diffraction?XRD?exhibited the morphology and crystal structure of CoGa₂O₄.Rotating disk electrode?RDE?confirmed the four-electron pathway at the cathode during the oxygen reduction reaction?ORR?.Thermo gravimetric analysis?TGA?and X-ray photoelectron spectroscopy?XPS?illustrated that the high rate oxygen vacancy existed in the CoGa₂O₄.The oxygen vacancy of CoGa₂O₄ played an important role in catalytic activity.In a word,the prepared nano spinel bulk-like CoGa₂O₄ provided an alternative to the costly Pt in air-cathode for wastewater treatment.This measurement in this experiment mainly included:electrochemical impedance spectroscopy?EIS?,linear sweep voltammetry?LSV?,transmission electron microscope?TEM?,scanning electron microscopy?SEM?,rotating disk electrode?RDE?,Brunauer–Emmett–Teller?BET?,X-ray photoelectron spectroscopy?XPS?,X-ray diffraction?XRD?and thermogravimetric Analysis?TGA?.Through analysis it was concluded through analysis:the power output increased when the resistance reduced and reaction kinetics improved.Moreover,the larger specific surface area of prepared material,the more active site.The MFC's output was excellent.