Cathode Materials Preparation And Its Electricity Generation Performance In Microbial Fuel Cells

Microbial fuel cells (MFCs), one type of environmental friendly bio-technology, represent a device that transforms chemical energy in organic materials directly into electrical energy via electrochemical reactions. With the advantages of abundant fuels, mild operation condition and clean green, the MFCs have great potential in dealing with the supply of fossil fuels decline and environmental problems intensify. The instability, inefficiency, low power output and high cost are still the major drawbacks in the development of MFCs.According to low output and high cost of the MFCs, we prepared two types of cathode material and changed the configuration correspondingly. The experimental platform was designed and set up to research the material property, power output and operation condition. Then, compared and analyzed these factors to find and optimize the electrogenesis performance of MFCs. The thesis including the following parts:1,Generation 4.0 Partially quarternized Polyamidoamine (PAMAM) dendrimers with both quaternary ammonium groups and primary amines was prepared. Using template synthesis method, after the reduction reaction, we are able to produce Polyamidoamine (PAMAM) dendrimer encapsulated Platinum nanoparticles (Pt-DENs) with uniform diameters of 4 nm. Meanwhile, electrodeposition of Pt on carbon paper was performed in three-electrode system:Pt wire and Ag/AgCl were used as counter and reference electrodes while carbon paper serves as working electrode. Pt nanoparticles deposited and dispersed uniformly on the whole surface of the carbon paper with a diameter of 300 nm.2,A simple air-cathode single chamber microbial fuel cell (SCMFCs) system was designed in this paragraph. Compared the two kinds of synthesis method between Pt-DENs and electro-deposition Pt. we analyzed the time-voltage curve, polarization and power density curve:using the Pt-DENs as the cathode catalyst, the SCMFCs acquired the largest power output of 630 mw/m2, open voltage of 0.5 V, as well as with lower Pt loading amount of 0.1 mg/cm2. With advantages of unique catalytic properties, including high activity, selectivity and stability, Pt-DENs show great potential in the application and development of MFCs.3,In this study, flower spherical copper indium disulfide (CuInS2) semiconductor microspheres, prepared by a facile solvothermal method, formed on the transparent conductive glass (ITO substrate) by spin-coating, could be en effective cathode material in a MFC system. EDX and ICP-AES have shown that an excess of indium was obtained, which was greater at the surface than in the bulk. XRD reveals the chalcopyrite structure of CuInS2. The positive slope of the Mott-Schottky plot confirms the formation of n-type CuInS2 composites. Cyclic voltammetric measurements showed oxidation and reduction potential of the microsphere were 1.2 V and-0.7 V; time-voltage curve shows the operation voltage of the MFC system was 0.55 V; Furthermore, being equipped with CulnS2 cathode, the MFC achieved open voltage of 0.69 V, maximum power density of 1640 mW/m2. largest current density of 17600 mA/m2. The CuInS2 photocathode MFC achieved excellent electricity performance even without a catalyst so that greatly reduces the material cost, which may broaden its application in energy conversion and environmental protection, and open up a new way for further development of the MFCs.