Fabrication Of ZnO Nanocomposite Structure On Stainless Steel And Its Photoelectric Sensing Performance

Photoelectrochemical?PEC?sensors have better linear range,lower sensitivity and detection limit,combinating semiconductor optics and electrochemical performance,comparing with electrochemical sensors.ZnO semiconductor materials can be used as one of the suitable electrode materials for photoelectric sensors,because of its fast light response,good chemical stability and excellent biocompatibility.However,pure ZnO can only be activated under UV light and the photogenerated electrons and holes can easily recombine.Ag₂S,a narrow band gap semiconductor,can broaden the visible spectrum utilization region.graphene oxide?GO?can quickly transfer the carriers generated by Ag₂S and ZnO.Therefore,in this work,we explored the optimum conditions for rapid preparation of ZnO nanorod arrays by microwave hydrothermal method.Ag₂S nanoparticles were loaded on the ZnO nanorod arrays,and then graphene oxide?GO?was electrodeposited to prepare GO/Ag₂S/ZnO composite photoelectrode.The prepared nanocomposition GO/Ag₂S/ZnO can realize the ultra-low concentration sensing of glycine?Gly?.The main contents are as follows:?1?ZnO nanorod arrays were fabricated on 316L stainless steel substrates by microwave hydrothermal method.The optimum conditions for rapid fabrication of ZnO nanorod arrays by microwave hydrothermal method with precursor concentration and microwave hydrothermal times as variables were investigated.The results showed that when the concentration of precursor solution was 0.05 M and the number of microwave hydrothermal cycles was 8 times,the optical current density of ZnO nanorod arrays reached the maximum(37.6?A?cm^-2).It showed that the ZnO nanorod arrays can be used as PEC sensors in the field of photoelectrochemistry.The sample electrodes were used for the photoelectrochemical detection of hydrogen peroxide and glucose.The results showed that Z5-8s photoelectrodes had high sensitivity,acceptable linear range and low detection limit.?2?Ag₂S nanoparticles were deposited on zinc oxide nanoarrays by Successive Ionic Layer Adsorption and Reaction?SILAR?method,and graphene oxide films were further deposited on the Ag₂S/ZnO composite structure.GO/Ag₂S/ZnO composite electrodes were fabricated successfully and used as photoelectrochemical detector for glycine.The electrodes showed a linear range of 5 nM-99.775 uM in Gly detection.The sensitivity was 5.44?A^-1?nM^-1?cm^-22 and the detection limit?LOD?was 3 nM?S/N=3?.The results showed that the composite electrodes had a high sensitivity,a good linear range and a low detection limit,as well as good selectivity and stability.