Mechanism And Regulation Of Go Reduced By Bacillus Sphaericus

Reduced graphene oxide(RGO),with advantages of adsorption sites,small resistance and strong plasticity,has been widely used in the fields of environmental contaminant remediation,hydrogen storage and electronic meterials.Methods of reducing graphene oxide(GO)include thermal,optical,microwave,chemical reagents,solvent thermal reduction,electrochemistry,biomolecules,plant extracts and microbial reduction.Among the methods for the reduction of GO,microbial reduction has the advantages of large yield,simple operation,low cost and the RGO synthsized by bacteria has strong dispersibility in water,which makes it more widely used in the field of water environmental remediation and has attracted the attention of scholars in the industry.However,microbial synthesized RGO is restricted by long growth cycle and low reduction efficiency,so it is important to find ways to improve the efficiency.Therefore,this paper focuses on the ability of microorganisms to successfully reduce go,regulate its reduction efficiency and improve its output.Main contents of this paper:(1)synthesis reduced graphene oxide by Bacillus sphaericus and characterization;(2)regulate nutrient sources of the bacteria to improve reduction efficiency;(3)regulate the effect of electron shuttles on reduction process,and come up with the mechanism of reducing GO by Bacillus sphaericus.The results are as follows:(1)Ultraviolet spectrophotometric analysis,X-ray powder diffraction analysis,fourier infrared and Raman characterized that GO can be reduced by Bacillus sphaericus and the oxygen-containing functional groups(C-O-C,O-H,C=O)on GO were reduced.(2)The microbial growth environment factors(p H,carbon source,nitrogen source,different kinds of bacteria and fungus fluid dosing amount)influenced the reduction efficiency.The results showed that,when p H=7,the inoculation amount of the bacterial solution was 10%,the only carbon source was glucose,the only nitrogen source was KNO₃,and the reaction time was 8 days,the reduction of graphene oxide by Bacillus sphaericus was the best(I_D/I_G=1.85).(3)The promotion effect of anthraquinone-2,6-disulfonic acid sodium(I_D/I_G=2.23)was better than that of anthraquinone-2-sulfonate sodium(I_D/I_G=1.15).The mechanism of microbe extracellular electron reduction graphene oxide was proposed at last:with extracellular respiration,Bacillus sphaericus transports electrons to attacks and reduces the oxygen-containing functional groups on the GO layer.