Preparation Of Novel Ce/Bi/CNT-PbO₂ Electrode For Metronidazole Removal In Water Solution

Metronidazole?MNZ?is a typical antibiotic drug,which is easy to dissolve in water and difficult to be degraded by microorganisms.Long-term retention in the environment can cause harm to human body.Th e electrochemical oxidation method represented by the lead dioxide electrode can efficiently remove metronidazole in water,and provide a feasible way for the treatment of metronidazole in water.However,the lead dioxide electrode coating is easy to fall off and the current efficiency is not high enough,so that its electrocatalytic activity is greatly reduced,and it is necessary to overcome the above disadvantages by modification.A cerium nitrate/nitric acid nitrate/carbon nanotube modified lead dioxide electrode?abbreviated as Ce/Bi/CNT-PbO₂ electrode?was prepared by electrochemical deposition technology in an electroplating solution containing cerium nitrate,bismuth nitrate and carbon nanotubes.Scanning electron microscopy,X-ray diffraction,linear voltammetry and cyclic voltammetry were used to analyze the morphological and electrochemical properties of different electrodes.It is known that Ce/Bi/CNT-PbO₂ electrodes have better surface structure and electrochemistry performance.The experiment of removing metronidazole in water showed that the Ce/Bi/CNT-PbO₂ electrode has higher oxygen evolution overpotential and stability,and the reaction accords with pseudo first-order kinetics.In the solution after degrading metronidazole for 120 min,the toxic heavy metal ions such as Sb³⁺,Bi³⁺and Sn⁴⁺were not detected by inductively coupled plasma mass spectrometry,and the dissolved concentration of Pb²⁺was 0.007 mg/L lower than the drinking water quality standard of World Health Organization,indicating that the modified electrode has safe use performance.By analyzing the intermediate products of degrading metronidazole measured by gas chromatography-mass spectrometry and ion chromatography,it can be inferred that the Ce/Bi/CNT-PbO₂ electrode finally degrades metronidazole into H₂O and CO₂.This paper uses the response surface design method to optimize the degradation experimental conditions and it is more conducive to the practical application of modified electrodes.Studies have shown that the Ce/Bi/CNT-PbO₂electrode may be a promising functional material for the treatment of antibiotic wastewater.