Synthesis Of Au/g-C₃N₄ Heterostructure And Its Applications In Electrochemical Sensors

The abuse of drugs and the increasing water pollution have brought serious damage to human being.Thus,accurate and rapid determination of such compounds is of great significance.Electrochemical technique has attracted great attention for its advantages,such as quick response,high sensitivity,good selectivity,low cost,easy operation,simplicity,in situ analysis and without any pretreatment.However,construction of an electrochemical sensor with high-performance based on favorable electroactive material remains a challenge.In this work,Au/g-C3N4 heterostructure with efficient interface was in situ prepared by using a single-source precursor.The Au/g-C3N4 exhibited enhanced electrocatalytic property and thus was employed to fabricate a novel electrochemical sensor for the determination of pollutants,including tetracycline,hydroquinone and catechol.The main research contents are as follows:Part Ⅰ:The Au/g-C3N4 heterostructure was synthesized by one-step calcination using melamine and chloroauric acid as raw materials.The as-prepared sample was characterized by TEM,SEM,EDS,XRD,XPS,UV-vis,FT-IR,BET and TG,which proved the intimate coupling between Au nanoparticles and g-C3N4Part Ⅱ:Au/g-C3N4 nanocomposite was modified on the surface of glassy carbon electrode(Au/g-C3N4/GCE).The as-fabricated sensor exhibited excellent analytical performance in the determination of tetracycline.The concentration linear range is 0.1～20 and 0.1～200 μM with a detection limit of 0.03 μM.Moreover,the sensor has good stability and anti-interference.Thus,the proposed method was successfully applied for the real sample assay.Part Ⅲ:Based on the enhanced electrocatalytic activity of Au/g-C3N4 towards phenolic compounds,the Au/g-C3N4/GCE sensor was used for the simultaneous determination of hydroquinone(HQ)and catechol(CC).The results showed that the developed sensor possesses desired analytic performances in the simultaneous detection of HQ and CC.The concentration linear ranges of HQ and CC were 1～320μM and 0.1～330 μM,respectively.Their detection limit values were 0.3 μM and 0.04μM,respectively.Because of its good selectivity and repeatability,the Au/g-C3N4/GCE sensor was used for the simultaneous detection of HQ and CC in the real samples,and favorable results were achieved.In summary,the experimental results suggested that Au/g-C3N4 heterostructure is a promising electro-active material and can be applied for the electrochemical sensor.