Performance Study Of Functionalized Carbon Nanotubes And Polyaniline Based Modified Anode In Marine Sediment Microbial Fuel Cell

Microbial fuel cell (MFC) is new types of battery that microbial degrade theorganic matter to produce electricity by the way of metabolism. Sediment microbialfuel cell (SMFC) is one of novel concepts of the MFC that the anode is embedded insediments to allow the microbial directly to absorb to the anode and utilize organics aselectron donor sources. It provides a new way for the utilization of the sea sediment.Meanwhile, due to the simple battery configuration and its environmental friendliness,these result in the extensive concern of the researchers in related field.Output energy of the SMFC is low so that it limits its practical application. Amongvarious kinds of factors, the low electron transfer efficiency between the anode andthe bacteria is a key influence factors. Therefore, many researches focus on improvingthe performance of the anode. This paper discusses the modified anode how toinfluence on the properties of the SMFC. The results provide a theory basis for thepractical application of the SMFC, and their conclusions are as follows:(1) A FePc/MWCNTs compound is synthesized by the pyrolysis and it has beendeveloped the unique modified anode of the SMFC. The unique modified anode isprepared by applying the compound. The results show that the modified treatment canimprove the exchange current density and the kinetics of the anode. The potential ofthe modified anode decreases to-0.535V,23%lower than the unmodified anode. TheSMFC equipped with this modified anode shows the maximum power density of572.3mWm-2, which is2.6times higher than that obtained from the SMFC with theunmodified anode. Finally, according to hydrogen bonding formed between thecompound and the cytochromes, the orientation effect and Fe(III)/Fe(II) redox couple,a novel molecular synergetic mechanism is presented to explain the excellentelectrochemical performance.(2) The modified electrode which uses the way of electrochemical deposition isutilized as the anode of the SMFC. The results indicate that by electrodeposition,some conductive polyaniline are adhered to the surface of the anode so that itscapacitance increases significantly. When the multi-walled carbon nanotubes areadded to the aniline monomer, mechanical strength and electrical conductivity of polyaniline are improved. The SMFC equipped with the MWCNTs/PANI modifiedanode shows that the anti-polarization ability of the anode increases significantly. Themaximum power density of527.0mWm-2(1888.9mAm-2) is4times higher than thatof the unmodified anode. Finally, according to the pseudocapacitance of the PANIand the double-layer capacitor of the MWCNTs, the influence of N elements orquinone for microbial growth and biological capacitance, we analyze the possiblemechanisms for its high performance in the SMFC.(3) A PANI/MnO2compound is prepared by means of in situ chemical synthesis.The compound is used to prepare the PANI/MnO2modified anode. The results showthat the capacitance of the PANI/MnO2anode is higher than that of the PANI anode,the anti-polarization ability and cyclic stability is both improved. The SMFC equippedwith the PANI/MnO2modified anode shows the maximum power density of268.9mWm-2, which is2times higher than that obtained from the SMFC with theunmodified anode. These results indicate that the anode coated with capacitivematerial can reduce electrode polarization phenomenon and further improve theoutput energy of the SMFC. On the basis of the above conclusion, it can provide aguiding role for our researches.