Study On Preparation And Performance Of The Anode For Glycerol Enzymatic Biofuel Cell

Enzymatic biofuel cells(BFCs),which use enzyme as biocatalysts to convert chemical energy to electrical energy,are clean and efficient energy transformation equipment.The enzymatic BFCs show potential applications and distinct advantages such as more moderate temperature and wide resources.With the vigorous development of the biodiesel industry,more attention has been drawn to the utilization of biodiesel byproduct.Glycerol,a major biodiesel byproduct,is used as the substrate in enzymatic fuel cell.Through energy conversion,glycerol can be converted into clean energy,which not only is beneficial for the disposal of the by-product,but also provides a clean and reliable energy reuse.This paper mainly discussed the preparation of the anode for glycerol enzymatic biofuel cell,a total of two systems were investigated including glycerol catalytic enzyme bioanode using three-dimensional GN as the carrier and Meldola's blue as the mediator,and the glycerol catalytic enzyme bioanode without a mediator based on Nitrogen-doped Ordered Mesoporous Carbon(NOMC).Firstly,the preparation of three-dimensional graphene material was studied.Graphite oxide(GO)was synthesized according to a modified Hummers' method.GO aqueous solution was obtained by ultrasonic exfoliation of graphite oxide and then reduced by hydrothermal method to get three-dimensional graphene,which was synthesized under the optimized conditions.What's more,the three-dimensional graphene was characterized and analysed by XRD,FT-IR,Raman,SEM,TEM etc.The results showed that graphene materials with three-dimensional structure could be obtained by the hydrothermal self-assembled method,at the same time,thin,loose and porous three-dimensional graphene could be prepared by the freeze drying method.The pore size was between 4~15 nm,which suggests a relatively large surface area.Secondly,the glycerol catalytic enzyme bioanode was prepared by using three-dimensional GN as the carrier and Meldola's blue as the mediator.It was prepared on the glassy carbon electrode by using three-dimensional GN as the carrier,Meldola's blue as the mediator and Nafion as the cross-linking agent to immobilize glycerol kinase(GK)and glycerol-3-phosphate oxidase(GPO).In the experiment,solubility and redox properties of Meldola's blue were explored to determine the way to immobilize on the enzyme electrode.Then the glycerol catalytic enzyme bioanode was prepared and optimized by using cyclic voltammetry.The results showed that when the concentration of Nafion was 2%,the concentration of MB was 3 mmol/L and volume ratio of GK and GPO was 2:1,the catalytic current density of the enzyme modified electrode was 52.22 ?A/cm~2.Thirdly,glycerol EBFC single cell was constructed by using carbon paper as a substrate electrode,the glycerol catalytic enzyme electrode modified by three-dimensional graphene prepared as the anode,the Pt/C catalyst as a cathode,Nafion membrane as electrolyte membrane.The working conditions were optimized and the performance was also evaluated by using polarization curve method and AC impedance method.The results showed that the glycerol EBFC had good discharge performance.The open circuit potential was 0.77 V and the maximum power density was 42.05 ?W/cm~2 at 0.42 V.Finally,the glycerol catalytic enzyme bioanode without a mediator based on Nitrogen-doped Ordered Mesoporous Carbon(NOMC)was prepared.The electrode was prepared on the glassy carbon electrode by using lab made NOMC as the carrier,Nafion as the cross-linking agent,GK and(GPO)as enzyme catalyst.The results showed that the NOMC exhibited a highly ordered mesoporous pore,and did not change the activity of the enzyme when used as the carrier.And the maximum catalytic current of the enzyme modified eletrode was 188.25 ?A/cm~2.Therefore,it can be used as the enzymatic biofuel cell anode which uses glycerol as a fuel.The usage of glycerol as the fuel of the enzyme biofuel cell provides a clean and reliable energy reuse method for the treatment of biodiesel byproduct,which is of great significance to the development of biodiesel technology.