Fabrication And Application Of Non-mercury Film Electrodes For Heavy Metal Ions Determination

Non-mercury film electrodes have some advantages such as non-toxicity,ease of preparation,renewal of surface and so on.In this thesis,the different film electrodes were prepared,The films' morphology have been charactered by SEM.Pb²⁺ and Cd²⁺ were simultaneously detected by SWASV.The effects of non-mercury film electrodes,which were prepared under different conditions on the response for HM have also been studied.1)The hydrogen bubble template method was applied to prepare bismuth film electrode,and Pb²⁺ and Cd²⁺ were simultaneously detected by SWASV,results showed the electrode that prepared under 525 mA/cm2 deposited current density,deposited time of 5 s had the best response.The optimum preconcentration time was 120 s.Respectively,the sensitivity were 0.44,0.91 ?A/?g·L-1.However,the bismuth film was easy to fall off during the test process,and the repeatability and stability of the electrode was poor.2)In order to improve the stability of the electrode,electrode modified with PEDOT and Bi,and Pb²⁺ and Cd²⁺ were simultaneously detected by SWASV.Results showed that PEDOT/Bi electrode which was prepared by deposited voltage of 1.1 V,deposited time of 10 min had the best response to Pb²⁺ and Cd²⁺.Respectively,the sensitivity were 1.24,1.85 ?A/?g·L-1.And RSD were 2.83%,6.68%,proving that the electrode had good reproducibility.Interference experiment proved it was minimum interference.3)The hydrogen bubble template method was applied to prepare antimony electrodes,Pb²⁺ and Cd²⁺ were simultaneously detected by SWASV,results showed the electrode that prepared under 525 mA/cm2 deposited current density,deposited time of 10 s had the best response to lead and cadmium.The sensitivity of Pb²⁺ and Cd²⁺ were 0.34,0.07 ?A/?g·L-1,its sensitivity was very low,in order to improve antimony electrode,bismuth and antimony composite electrode was prepared.Results showed that the peak current was high,and exhibited good linear behavior,the sensitivity of Pb²⁺ and Cd²⁺ were 0.65,0.61 ?A/?g·L-1.These all non-mercury film electrodes have good response to heavy metal ions,which indicate that this film electrodes have great application and potential markets.