Preparation Of Molybdenum Disulfide/Carbon Nanospheres Composite And Electrochemical Sensing Of 4-Aminophenol And Acetaminophen

4-Aminophenol?4-AP?and acetaminophen?ACAP?have posed a major threat to the water environment and human health due to their high production and non-standard use.4-AP is an intermediate material for the synthesis of azo dyes and also widely used in the synthesis of antioxidants and developers.It usually exhibits dual toxicity of phenol and aniline,which will destroy the DNA structure,lead to gene mutation and produce strong carcinogenicity.ACAP is a common anti-inflammatory,antipyretic and pain-relieving drug,which is widely used in clinical practice.It is also an intermediate in organic synthesis,a stabilizer for photographic chemicals and hydrogen peroxide.Excessive accumulation of ACAP in the organism can cause damage to the liver and kidney,which is of great significance for their detection.Molybdenum disulfide?MoS₂?has great application potential in the field of electrochemical sensing due to its graphene-like structure,ultra-thin sheet thickness,excellent physical and chemical,electrical and optical properties.Furthermore,carbon nanospheres have been widely used in the field of electrochemistry because of their good thermal stability,large specific surface area,and good electrical and thermal conductivity.In this thesis,MoS₂/carbon nanosphere composites with different morphologies and structures were prepared,and the synergistic effect of MoS₂ and carbon nanosphere was used for the detection of 4-AP and ACAP.The experimental results show that the electrochemical sensor can achieve high sensitivity and high selectivity detection.The main work is as follows:?1?MoS₂@carbon microsphere composites were synthesized by one-step hydrothermal method.The composite was characterized by scanning electron microscopy,transmission electron microscopy,Raman spectroscopy and X-ray diffractometry.An electrochemical sensor was constructed based on the nanocomposite modified glassy carbon electrode?GCE?.The sensor has good electrochemical response to the redox reaction of 4-AP.Under the optimal conditions,the concentration of 4-AP show a good linear relationship with the peak current in the range of 0.01¹8.00?M,and the detection limit is 3.0 nM.The sensor also has good repeatability,stability and selectivity.?2?Polydopamine/silica was obtained by spontaneous polymerization of dopamine on the surface of silica,and HCSs was obtained by etching silica with hydrofluoric acid after carbonization at high temperature.Then,NHCSs@MoS₂ composite was synthesized by hydrothermal method.The material was characterized by scanning electron microscopy,transmission electron microscopy,X-ray diffractometry,Raman spectroscopy and electrochemical impedance spectroscopy.The electrochemical behavior of ACAP on the NHCSs@MoS₂/GCE was investigated by cyclic voltammetry and differential pulse voltammetry.The results show that NHCSs@MoS₂ can significantly enhance the oxidation peak current of ACAP.The linear range of NHCSs@MoS₂/GCE for ACAP detection is0.05²0.0?M,and the detection limit is 0.012?M.?3?We further constructed a new electrochemical sensor for simultaneous detection of4-AP and ACAP by using NHCSs@MoS₂ nanocomposite as electrode modification material.The results of electrochemical analysis show that the NHCSs@MoS₂nanocomposite has a good electrochemical response to the redox of 4-AP and ACAP,and both 4-AP and ACAP present obvious redox peaks.The oxidation peak potential difference between 4-AP and ACAP reach 0.292 V.Under the optimal conditions,the linear detection range of 4-AP and ACAP is 0.05²0.0?M,and the detection limits are 0.013?M and0.020?M,respectively.Furthermore,the sensor has satisfactory stability,reproducibility and anti-interference ability.