Electrochemical Sensing Of Organic Pollutants In Environmental Water Based On Metal-Loaded BCN Nanocomposites

With the rapid growth of population and the excessive consumption of energy and resources,typical environmental organic pollutants such as nitrobenzene,paraquat and chloramphenicol pose a growing threat to human beings at the top of the food chain.Therefore,it is particularly important to develop rapid detection technologies for highsensitive pollutants.Compared with traditional pollutant detection technologies such as spectroscopy,chromatography and biological analysis,electrochemical methods have unique technical advantages such as rapid signal response,relatively simple equipment,more convenient operation,low and low detection limit At present,the detection method of pollutants based on electrochemical sensing technology still needs to be further improved,such as the complex components of biological samples,the changes of dissolved oxygen and temperature in the electrolyte will have a certain impact.In addition,the electrode conditions are also more stringent,sensitive to temperature and solution acidity changes.Recently,the modification of materials to modify electrodes has become one of the important ways to improve the performance of electrodes and the efficiency of electrical analysis,and has been widely used in the monitoring of toxic substances in various fields such as environmental protection,medicine,and food.Carbon nanomaterials have excellent mechanical flexibility,electrical conductivity,thermal and chemical stability,so they are often used in electrochemical sensing to achieve rapid detection of pollutants in the environment.However,pure carbon nanomaterials as electrode materials have certain limitations in catalytic activity.Therefore,metal was loaded on carbon nanomaterials to obtain better electrochemical response.In this paper,we have prepared three kinds of sensors for the detection of organic compounds in the environment.The main research contents are as follows:1.Single-atom niobium-doped boron-carbon-nitrogen nanotubes（SANb-BCN）were synthesized by template method for high-sensitivity electrochemical sensing of nitrobenzene（NB）.The morphology and physicochemical properties were characterized by X-ray diffraction（XRD）,transmission electron microscopy（TEM）,laser Raman spectroscopy,and scanning electron microscopy（SEM）.SANb-BCN was modified on bare glassy carbon electrode（GCE）to prepare SANb-BCN modified electrochemical sensor（SANb-BCN/GCE）.The electrochemical behavior of NB on the electrode was studied by controlling the electrochemical experimental conditions.Under the optimal experimental conditions,SAN b-BCN/GCE showed high selectivity and low detection limit（LOD）for NB.Finally,SANb-BCN/GCE was used to analyze the target pollutants in actual samples,and the results were good.2.Ferric oxide doped BCN nanosheets（Fe₂O₃-BCN）were synthesized by hydrothermal method,and a simple and low-cost Fe₂O₃-BCN/GCE electrochemical sensor was successfully constructed for the residual detection of paraquat（PQ）in the environment.Compared with other similar modified electrodes,Fe₂O₃-BCN/GCE showed low charge transfer resistance（Rct）and sensitive current signal response.Under the optimal experimental conditions,the developed electrochemical sensor has a wide linear range and low detection limit.In addition,the electrochemical sensor based on Fe₂O₃-BCN was successfully applied to the sensitive analysis of PQ in lake water and tap water with satisfactory recovery and linearity.3.BCN nanosheets and Cu-doped BCN nanosheets（Cu-BCN）were synthesized by chemical liquid deposition method,and electrochemical sensors for sensitive detection of chloramphenicol（CAP）in the environment were successfully constructed.The morphology and structure of the material were well characterized by a series of characterization methods.By comparing the electrochemical response of CAP on GCE,Cu/GCE,BCN/GCE and Cu-BCN/GCE modified electrodes,Cu-BCN/GCE showed excellent electrochemical sensing performance.The electrochemical behavior of CAP on electrode surface was determined by analyzing the relationship between current response and scanning rate.Subsequently,the experimental conditions were optimized,including the modification of Cu-BCN,enrichment time,deposition potential and pH value of electrolyte,and the optimal experimental conditions were obtained.Under these conditions,Cu-BCN/GCE showed excellent linearity and low LOD.In addition,the performance of the electrode was explored,and the results showed that CuBCN/GCE had excellent stability,reproducibility,repeatability,and anti-interference performance.