Preparation Of Modified Glassy Carbon Electrode And Its Application In Environmental Pollutants Detection

Electrochemical method,which to measure by using chemical modified electrodes,has fast response,cheap instrument,small volume,electrode preparation process is simple,high sensitivity,good reproducibility,and low cost etc,And it has been a hot research topic in the field of electrochemistry.This paper reports the multi-walled carbon nanotubes,nano gold solution and malachite green and so on as raw materials,Three kinds of chemically modified electrode: Carboxyl of multi-walled carbon nanotubes/chitosan modified glassy carbon electrode?c-MWCNTs/CS GCE?,Nanometer gold carboxyl of multi-walled carbon nanotubes/chitosan modified glassy carbon electrode?c-MWCNTs-Au/CS GCE?,Malachite green polyethylene modified glassy carbon electrode?PMG/GCE?.They were prepared respectively by drops of coating and electrochemical polymerization method.1.c-MWCNTs / CS GCE for detection of 2,4-dichlorophenol in Water: c-MWCNTs / CS GCE was prepared by drops of coating,The electrochemical behavior of 2,4-dichlorophenol on the modified electrode was studied by cyclic voltammetry,differential pulse voltammetry and chronoamperometry.The experimental results show that: The modified electrode significantly increased 2,4-dichlorophenol peak oxidation current than glassy carbon electrode.The electrochemical reaction of 2,4-dichlorophenol,which occurs on the modified electrode,is a two electrons and protons to participate in the complete irreversible reaction controlled by diffusion,Diffusion coefficient of 2,4-dichlorophenol is 1.5857×10^-5cm²·s^-1 under the test conditions.Linear detection range of 2,4-dichlorophenol between the peak current and the concentration were 0.1-1 mg/L?1-10 mg/L and 10-80 mg/L with a detection limit of 0.1 mg/L by cyclic voltammetry,R²>0.99.Linear detection range of 2,4-dichlorophenol between the peak current and the concentration were 0.1-1 mg/L?1-10 mg/L and 10-80 mg/L with a detection limit of 0.01 mg/L by differential pulse voltammetry,R²>0.99.2.c-MWCNTs-Au / CS GCE for detection of sodium nitrite in Water: c-MWCNTs-Au / CS GCE was prepared by drops of coating,The electrochemical behavior of sodium nitrite on the modified electrode was studied by cyclic voltammetry,differential pulse voltammetry and chronoamperometry.The experimental results show that: The modified electrode significantly increased sodium nitrite peak oxidation current than glassy carbon electrode.The electrochemical reaction of sodium nitrite,which occurs on the modified electrode,is a two electrons and zero protons to participate in the complete irreversible reaction controlled by diffusion,Diffusion coefficient of sodium nitrite is 1.5857×10^-5cm²·s^-1 under the test conditions.Linear detection range of sodium nitrite between the peak current and the concentration were 0.8-10 mg/Land 10^-500 mg/L with a detection limit of 0.1 mg/L by cyclic voltammetry,R²>0.99.Linear detection range of sodium nitrite between the peak current and the concentration were 0.05-1 mg/L and 1-150 mg/L with a detection limit of 0.01mg/L by differential pulse voltammetry,R²>0.99.3.PMG/GCE for detection of phosphate in Water: PMG/GCE was prepared by cyclic voltammetry electrochemical polymerization,The electrochemical behavior of phosphomolybdic acid on the modified electrode was studied by cyclic voltammetry,differential pulse voltammetry.The experimental results show that: The electrochemical reaction of phosphomolybdic acid,which occurs on the modified electrode,is a two electrons and protons to participate in the completely reversible reaction controlled by diffusion,Diffusion coefficient of phosphomolybdic acid is 7.258502×10^-6 cm²·s^-1 under the test conditions.Linear detection range of phosphate between the peak current and the concentration were 0.1-1 mg/L and 1-12 mg/L with a detection limit of 0.04 mg/L by cyclic voltammetry,R²>0.99.Linear detection range of sodium nitrite between the peak current and the concentration were 0.08-1 mg/L and 1-12 mg/L with a detection limit of 0.01mg/L by differential pulse voltammetry,R²>0.99.