Amperometric detection of nitrate using Sn-CuxO nanocomposite

2021FEBEREC-STD-103This thesis presents a comprehensive investigation into the structural, physical, and electrochemical characteristics of CuxO and Sn-doped CuxO nanocomposite thin films as catalysts for the amperometric detection of nitrate. Excessive Nitrate is harmful to human thus the motivation of this work. The unique electrochemical and electronic properties of CuxO (Cu2O/CuO) gives it merit to be used in the development of electronic devices. The nanocomposite thin films were constructed by a simple chemical route, a two-step spin-coating method and calcination technologies. The study involves X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) for physical characterization. The XRD analysis reveals the presence of cubic Cu2O and monoclinic CuO phases in pristine CuxO, while Sn doping induces crystallographic changes. Doping with Sn led to an increase in the quantity of electron transfers, increasing from 1 to 2 when compared to undoped CuxO.The electrochemical characterization, performed through cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) in alkaline electrolyte, evaluates the catalytic performance for nitrate detection.2021FEBEREC-STD-103 本论文针对CuxO及掺锡CuxO纳米复合薄膜作为硝酸盐安培检测催化剂的结构、物理及电化学特性开展了系统性研究。硝酸盐过量摄入会对人体健康造成危害，这亦是本研究的核心动机。CuxO（Cu₂O/CuO）兼具独特的电化学与电子特性，使其在电子器件开发领域具备应用价值。本研究通过简易化学路径——两步旋涂法结合煅烧工艺——制备得到目标纳米复合薄膜。研究采用X射线衍射（X-ray Diffraction, XRD）、扫描电子显微镜（Scanning Electron Microscopy, SEM）及X射线光电子能谱（X-ray Photoelectron Spectroscopy, XPS）完成样品的物理表征。XRD分析结果显示，纯相CuxO中存在立方相Cu₂O与单斜相CuO，而锡掺杂会引发晶体结构的变化。与未掺杂的CuxO相比，锡掺杂使得电子转移数从1提升至2。本研究通过循环伏安法（Cyclic Voltammetry, CV）、计时电流法（Chronoamperometry, CA）及电化学阻抗谱（Electrochemical Impedance Spectroscopy, EIS）在碱性电解液中开展电化学表征，以评估其用于硝酸盐检测的催化性能。