Preparation Of Carbon Composite Materials And Its Application In The Detection Of Heavy Metals

Heavy metal pollution is a major problem which is damaging the world today.The heavy metals which are toxicity,non-biodegradable,and cumulative are seriously harmful for human body health.Therefore,a fast and sensitive method for detecting heavy metals is particularly important,which is a hotspot of research in the world.Currently,the main heavy metal detection method is spectroscopy detection.Although these methods can obtain good results,its disadvantages are bulky and expensive,complex operation and no real-time detection.Recently,the electrochemical detection of heavy metals,with its low cost,simple operation,real-time detection become the ideal method for detecting of heavy metals.The materials for modified electrode are the key to electrochemical detection of heavy metals.Carbon materials,such as graphene,carbon nanotubes have huge specific surface area which can provide more active sites for heavy metal ions.Excellent electrochemical performance ensure the heavy metals to strive in the surface of the electrode fastly and improve the detection sensitivity.Single carbon material is easy to reunite and affect its excellent electrochemical performance.Polyaniline is typical of conducting polymer which has not only good electrical conductivity but also a variety of morphology.Its surface contains the amino groups,which can undertake complex coordination with heavy metal ions.1.In this paper,graphene-carbon nanotube-carbon microspheres composite material and graphene-carbon nanotube-carbon-polyaniline microspheres composite materials were prepared.The SEM,FTIR spectrometer and Raman spectrometer were used to characterize composite materials.It constructs a three dimensional conductive network,to expand the electrochemical activity areas by avoiding the accumulation,.2.Graphene-carbon nanotube-carbon microspheres material modified electrode was used for detection of Pb(?)in water.The effects of supporting electrolyte,pH,deposition potential,deposition time,carbon microsphere size and ratio of carbon materials for detection of Pb(?)were studied.The results showed that:the optimal experimental conditions were pH 4.5 HAc-NaAc,the deposition potential-1.2V,the deposition time 120s,1 um carbon microspheres and C1:1:1 materials when the detection limit was 0.8 nM.3.In this paper,We replaced the carbon microsphere with polyaniline microspheres,basing on the above experiments.The preparation of graphene-carbon nanotube-polyaniline microspheres composite material was introduced.The effects of supporting electrolyte,pH,deposition potential,deposition time for the detection of Pb(?),Cd(?)were studied.The results showed that:the optimal experimental conditions are pH 4.5 HAc-NaAc,the deposition potential-1.3V,the deposition time 120s,the concentration and peak current were a good linear relationship in the 0.2?M?1.0 ?M.The sensitivity for Pb2+,Cd2+were 57.05?A/?M and 47.35 ?A/?M.The detection limit for Pb2+,Cd2+were 0.3 nM and 0.4 nM,respectively.4.The preparation of graphene-carbon nanotube-polyaniline microspheres-bismuth ions composite material was introduced.We studied the influence of lead ion and cadmium ion detection with bismuth ions.The results suggested that the sensitivity of Pb2+,Cd2+ can be increased by double.The sensitivity for Pb2+,Cd2+ were 102.81 ?A/?M and 109.83 ?A/?M.The detection limit for Pb2+,Cd2+ were 0.2 nM and 0.1 nM,respectively.The actual samples test results with RGO-MWCNTCOOH-PAN-Bi3+ modified electrochemical sensor were similar with ICP-MS.The results showed that the electrochemical sensor can make actual detection.