Preparation And Electrochemical Performance Of Carbon Nanotubes Supported Au Nanoparticles

Since their discovery in1991, carbon nanotubes （CNTs） have become the focus becauseof their excellent physical and chemical properties. Compared with traditional materials,carbon nanotubes can provide adequate reaction sites for the electrochemical reactionsbecause of their large surface area. On the other hand, the metal nanoparticles also haveunique chemical and physical properties due to their large surface area and high surfaceactivity. They have been applied to electricity, catalysis and other fields. Composites based oncarbon nanotubes and metal nanoparticles have been widely used in research fields such aselectrochemical sensors, catalysis, photocatalysis and so on. Carbon nanotubes supportedmetal nanoparticles show superior improvment of the electrochemical performance. Based onthese reasons, this work focuses on preparation, characterization and electrochemicalperformance of carbon nanotubes supported gold nanoparticles.1Vertically aligned carbon nanotubes supported gold nanoparticles were prepared bymagnetron sputtering deposition. The Au/VACNTs nanoomposite was characterized by SEM,TEM and XRD. The electrode based on Au/VACNTs was used to electrochemical detection ofmethyl parathion （MP）. The results show that the sensitivity of the composite electrode is4.5times of that of the pure carbon nanotube array electrode. The linear range is0.2^-16.0mg/mL（S/N=3）, the detection limit is0.050mg/mL and the sensitivity is1.91mA mg^-1mL^-1.2The gold nanoparticles modified multi-walled carbon nanotubes （MWCNTs） werepreparied using ethylene glycol reduction method. Firstly, MWCNTs were functionalized byimmersing in mixed acids. Then, metal precursor, HAuCI₄·3H₂O was reduced by ethyleneglycol in a solution containing sodium borohydride as reducing agent, sodium citrate as astabilizer. The Au nanoparticles loaded carbon nanotubes composite was characterizatiedusing TEM, XRD, infrared spectrometer. The results show the gold nanoparticles weresucceefully supported onto the carbon nanotubes.3Kojic acid was studied by electrochemical detection in the optimized condition withgold nanoparticles-loaded carbon nanotubes composite as modified electrode （Au/MWCNTs）.Experimental results show that the composite materials have good catalytic performance forkojic acid, the linear range is1×10^-3-5.5×10^-3mol/L （S/N=3）, the limit of detection is2.0×10^-5mol/L. The composite materials by ethylene glycol reduction preparation have widelinear range, high sensitivity for kojic acid.