The Study Of Microbial Fuel Cell Cathode Catalyst And Production Of Electrical Properties For Pesticide Wastewater Treatment

Microbial fuel cells ?MFCs? is a novel electrobiochemical system using sewage microorganisms as biocatalysts to degrade wastewater containing organic pollutants and generate electricity, which can turn wastage into available material. As a new way of energy recovery and sustainable development of water resources, MFCs have attracted the comprehensive attention of chemists around the world. Platinum ?Pt? and its alloys have long been regarded as the best electro-catalysts for the oxygen reduction reaction ?ORR? at the cathode of MFCs, however, Pt-based catalysts have disadvantages of the high cost, poor durability and limited reserve in nature, which hampered the magnification and commercialization of MFCs. Therefore, the studies of ORR catalyst with high performance and low cost have important theoretical and practical significance for MFCs.In this paper, we used the pesticide factory wastewater as the substrate of MFCs in order to treat with wastewater and generate electricity. Two hetero atom-doped carbon catalysts were prepared and applied to single chamber air cathode MFCs for improving their performance of electricity generation. We studied the effect of heteroatom doping on ORR catalytic air cathode by means of analyzing the catalyst's morphology, microstructure and oxygen reduction catalytic activity and so on. These results will have great significance for promoting MFC in large-scale commercial application of sewage treatment. The research results of this dissertation consist of the following two parts:Firstly, N-doped carbon catalyst was synthesized successfully by direct pyrolysis of cellulose paper under NH₃ atmosphere and possessed a large surface area ?1294.9 m²/g?. The electrochemical studies revealed that the N-doped carbon material has high electro-catalytic activity in the oxygen reduction reaction under neutral conditions. The material characterization of N-doped carbon catalyst exhibited its maximum power density of 1041±90 mM/m² is higher than that of commercial Pt/C material ?584±10 mM/m²?. Both the nitrogen dopant and the large surface areas were considered to play a key role in the improved performance of the catalyst. The preparation of this N-doped carbon material is cost-efficient and easily to be scaled-up. so this catalyst is promising for application in MFCs.Secondly, N and F co-doped carbon material was successfully prepared by the direcet pyrolysis of a mixture of PTFE and BP-2000 under NH₃ atmosphere. The BP-NF catalyst exhibited better catalytic performance ?high onset potential and limiting current density? than that of single N or F doped carbon materials. Our results demonstrated the synergetic ORR electrocatalytic effect of this material high catalytic performance. The MFCs with BP-NF as the cathode catalyst generated a high maximum power density of 672 mM/m² and an open circuit voltage of 749 mV. The results was higher than that of the commercial Pt/C catalyst ?572 mM/m²,693 mV?, and also higher than BP-N ?588 mM/m²,655 mV? and BP-F?524 mM/m²,645mV?. The raw materials of this catalyst are commercial and low cost, and the preparative method is facile and easily scaled-up. This study provides a new method for the preparation of highly efficient ORR catalysts of MFCs.