Study On The Detection Performance Of Trivalent Arsenic Based On Fe₃O₄-rGO Nanocomposite

Nowadays,environmental pollution has caused great harm to human health and life,especially heavy metal pollution in water is closely related to us.Among them,the metalloid arsenic is one of the heavy metal pollution that cannot be ignored.In terms of toxicity,As³⁺far exceeds As⁵⁺.The detection of arsenic in water has always been the focus of environmental pollution research.Although the traditional methods have achieved some results,the complexity of the sample processing process,the expensive equipment and the long detection cycle have restricted its further development.In contrast,the electrochemical detection method has its unique advantages.In this thesis,the glassy carbon electrode was modified by Fe₃O₄-rGO nanocomposite material,and the trace trivalent arsenic in water was detected by electrochemical methods,and the final detection results were obtained.The main work is as follows:1.Fe₃O₄nanoparticles have good selectivity and adsorption to trivalent arsenic.Reduced graphene oxide（rGO）has good conductivity.Its layered structure makes it have a large surface area,allowing Fe₃O₄nanoparticles to fully adhere.The Fe₃O₄-rGO nanocomposite material was successfully prepared,and the diameter of Fe₃O₄nanoparticles was about 20nm.Using electron microscope,Raman spectrometer,Fourier infrared spectrometer,electrochemical workstation and other instruments,a series of physical characterization and electrochemical characterization were carried out,and related physical and chemical properties were obtained.2.The glassy carbon electrode was modified with Fe₃O₄-rGO nanocomposite material,and the square wave voltammetry was selected for electrochemical test.In the final detection result,we found that the peak current response signal far exceeds that of other papers,about seven times,which is also conducive to improving the anti-interference of the signal.Moreover,the most important sensitivity and linearity ranges are 2.15μA/ppb and 1-20ppb,respectively.Compared with other papers,each has its own advantages and disadvantages.In the end,the detection limit calculated was 1.19 ppb,which far reached the standard of 10 ppb stipulated by the WHO.3.In order to simulate the situation of real water samples,interference experiments were carried out,and the results found that the error was only about 1%,which is also better than other papers.In the subsequent stability and repeatability studies,the errors were about 1%and 0.5%,respectively.It provides feasibility for future application in actual testing.