Electricity Production And Pollutants Removal Performance By Photocatalytic Microbial Fuel Cell

Microbial fuel cell is a kind of new technology, which can remove pollutant and generate electricity at the same time. Photocatalytic microbial fuel cell could generate electrity and cause photoelectric effect in the light. This technology provides the technologyical possibility to couple the solar energy with the biomass. The powder titanium dioxide was the most commonly used photocatalytic cahode in the studies of microbial fuel cell. The band gap of titanuim dioxide is 3.2 e V. It is only exicited by ultraviolet light of solar spectrum which wavelength less than 380 nm.Microbial fuel cell and polycrystalline silicon solar cell(MFC-PSSC) was constructed and the feasibility of the photocatalysis microbial fuel was preliminay studied. Two kinds of photoelctron in the copper surface which was excellent conductivity were compared. Then the photoelectron and photohole will be transfer to the circuit system. The reaction rate of photocatalytic cathode will be speed up. The electricity generation of photocatalysis microbial fuel was preliminary analyzed. The pollutant removal efficiency and the mechanism were preliminary studied in the MFC.The main contents of this paper are as follows.(1)A new microbial fuel cell-polycrystalline silicon photocell was prepared through microbial fuel cell and polycrystalline silicon photocell connection in series. The output voltage and power density were measured. When the MFC-PSSC was transform light from darkness, the voltage increased from 0 V to 1.184 V. The MFC-PSSC responded obviouly to light, and had a significant photocell characteristica. The results showed that the power density of MFC could reach 76.2 m W·m-2, the power density of sterilized Cell-PSSC could reach 285.2 m W·m-2, and the power density of MFC-PSSC could reach 826 m W·m-2 in the light. The power density of MFC-PSSC in the light was higher than MFC and sterilized Cell-PSSC. And the MFC-PSSC could accelerate the degradation of organic pollutants in the anode chamber and the degradation of Cr(Ⅵ)in the cahode chamber under light. The microorganism in the anode chamber under darkness and light were anlyzed by 16 Sr DNA. The results showed that the microorganism and microbial diversity reduced. A high current could inhibit the microorganism. And the inhibition of the electricity production bacteria was less than that of the non-electricity production bacteria.(2) A Cu O electrode based on copper was prepared. The electrode was used as cathode in photocatalytic microbial fuel cell. The output voltage, linear scanning current curve and electrochemical impedance spectroscopy was tested. The results showed that the output voltage and linear scanning current were increased in the photocatalytic microbial fuel cell under light. And the electrochemical impedance was reduced in the photocatalytic microbial fuel cell under light. The linear scanning current and electrochemical impedance in the photocatalytic microbial fuel cell under light and darkness were contrastive analyzed. The mechanism of photocatalytic microbial fuel cell was analyzed and summarized. The photohole and photoelectron were generated in the Cu O cathode under light, the rate of electron oxidized was accelerated by the photohole. That process could increase the cathodic potential and reduce the cathode resistor.(3) A Cu In S2 electrode based on copper was prepared. The electrode was used as cathode in photocatalytic microbial fuel cell which cathode chamber was Methyl Orange. The output voltage, power density, open circuit voltage, linear scanning current curve and electrochemical impedance spectroscopy were tested. The performance of photocatalytic microbial fuel cell was affected by light in the anaerobic and aerobic conditions. The results showed that the performance of photocatalytic microbial fuel cell was enhanced under light. The methyl orange concentration in the cathode chamber was measured in the anaerobic and aerobic conditions. The results showed that methyl orange decolorizing efficiency was improved with the improvement of generate electricity. The methyl orange degradation efficiency and degradation product in photocatalytic microbial fuel cell were analyzed in the anaerobic and aerobic conditions. The process was preliminary analyzed that photohole was reduced by electron and the photoelectron was oxidized by electron acceptor in the cahode.(4)A new microbial fuel cell-photo degradation device was build by the output voltage of microbial fuel cell. The Cu2 O was used as cathode in the MFC. The decoloration of methy orange was measurement in the microbial fuel cell-photo degradation device. The results showed that low voltage of microbial fuel cell can improve the efficiency of photoelectrochemical degradation of pollutantion. The new direction for the application of microbial fuel cells can be expanded in this way.