The Study On The Preparation, Characterization Of Ceria Nanoparticles And Its Modification To Anode In Microbial Fuel Cell

Because of its many particular properties in optics, acoustics, electricity, magnetism, heat, catalysis, etc, ceria nano-particle has gained much attention of scholars from all over the world. Until now ceria nano-particle has been applied widely in the fields of catalyst, superconductor, ceramic, oxygen sensor, electrolytes in solid oxide fuel cells(SOFCs), glass-polishing materials and electrode materials, etc. Ceria nano-powder was prepared by sol-gel method in this paper. It was used to modify the anode in microbial fuel cell (MFC), which enhanced the electricity production of MFC. The main contents and results of this dissertation are summarized as follows.(1) Cerium (Ⅲ) nitrate, citric acid and PEG2000 were chosen as the materials to prepare CeO2 nano-powders via sol-gel method. TG-DTA, XRD, and TEM were used to characterize precursors of ceria and ceria products. The result showed that the best conditions of preparing nano-ceria was as follows:molar ratio of cerium nitrate to citric acid was 3:1; the addition of high purified water was 20mL; the concentration of PEG2000 was 0.6%; pH of citric acid solution was not necessary to adjust; the reaction temperature was 65℃; drying temperature of gel was 105℃; roasting temperature was 500℃under atmosphere of air.(2) This paper prepared two kinds of electrodes made by sol-dipping method and solution-dipping method respectively. The electrode modified by sol-dipping method was characterized by electrochemical methods. The result showed that the electrode modified by sol-dipping method may promote the redox reaction of certain substances in anodic solution. When the microbes was present, the catalysis was not effecitive, which may be caused by the covering of redox active sites.(3) To use the two electrodes as the anode of MFC, the result showed that anode modified by sol-diping method had positive effect for improving efficiency of the generation of electricity, the best power density is 2.19W/m2 which was more than the unmodified one with the largest power density 1.81 W/m2. In contrast, the other anode modified by solution-dipping method has negative effect for the generation of electricity. The best power density is 1.28 W/m2 which is less than the unmodified one with the largest power density 2.07 W/m2.