Research On Heteroatom-doped Carbon-based Materials In Microbial Fuel Cells

As the global population continues to grow,fossil fuels are about to run out,global environmental issues are becoming more pressing,and people are increasingly demanding environmentally friendly new energy and new technologies.Microbial Fuel Cells(MFCs)are new bio-electrochemical devices that use microorganisms to directly convert the chemical energy in any biodegradable organic waste into electrical energy,and at the same time can treat wastewater.Due to the low output current and high cost limits the large-scale practical application of microbial fuel cells,and the slow kinetics of the oxygen reduction reaction(ORR)of the cathode is an important factor affecting the development of MFCs.Therefore,it is necessary to develop an ORR catalyst with low cost,high catalytic activity and good stability.Through literature research,it is found that hetero-doped carbon based materials have excellent ORR catalytic activity and stability,and are widely used in new energy and other fields.c According to the above problems,the main research contents of this article are as follows:1.Through a simple one-step pyrolysis method,the calcination temperature is1000℃,using inexpensive polyaniline as a carbon source and a nitrogen source,and a composite material of polyaniline and boric acid as a precursor,a nitrogen-boron co-doped carbon material is synthesized(PANI/B-n,where n is the amount of boric acid),which exhibits excellent oxygen reduction catalytic activity in both alkaline and neutral solutions.Among them,the initial potential of PANI/B-8 in the electrolyte of0.1 M KOH and 0.1 M phosphate buffer solution(PBS)can reach 0.93 V and 0.89 V,respectively.which can match or even better than commercial Pt/C.In addition,a series of physical characterization of the catalyst material was performed to analyze the effect of boron doping on the physical structure and element composition of the carbon-based material.Applying these catalysts to the cathode of a microbial fuel cell.We additionally tested the output current and the highest power density of PANI/B-8-MFC when the catholyte is neutral and alkaline,both showing compared to commercial Pt/C 20 wt%excellent performance,and the power generation performance under alkaline conditions is better than that under neutral conditions.2.A multi-walled carbon nanotube was used as the carbon source,and a fluorine source was provided by polytetrafluoroethylene to prepare a fluorine-doped carbon-based composite material as an ORR catalyst,in which temperature was used as a comparative condition.A series of physical characterization techniques are used to test the synthesized material and analyze its morphology and structure.O-CNTs-F-800 has highly efficient ORR catalytic activity in 0.1 M KOH solution,and its starting point reaches0.82 V.As a cathode catalyst for microbial batteries,O-CNTs-F-800 shows excellent power generation performance,and its output power density is as high as 597.23 m W m-~2.