Electrical and Humidity Sensing Properties of K+-Nano-Mica Film and Determination of Copper(II) Ion Using Diazo-Modified Au Electrode

• Main Authors: Lin, Po-Hung, 林泊宏
• Other Authors: Su, Pi-Guey
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/59717716416399177958

碩士 === 中國文化大學 === 化學系應用化學碩士班 === 101 === Electrical and humidity sensing properties of K+-nano-mica film An impedance-type humidity sensor was made using K+-nano-mica film. Complex impedance spectra were obtained to analyze the humidity sensing and electrical properties of the humidity sensor. The sensor had a high sensitivity and its sensing-linearity depended on the applied frequency. The temperature dependence between 15 and 35℃ was from −0.1% RH/℃to −0.67% RH/℃ at 20–90% RH, respectively. The sensor exhibited a small hysteresis, a fast response time and good long-term stability. The different complex impedance plots obtained at low and high relative humidity indicated that the ions dominate the conductance of the K+-nano-mica film. Determination of Copper(II) ion using Diazo-modified Au electrode Novel sensitive electrochemical Cu(II) ion sensor were made by electrochemical coating functionalized calix[4]arenes with benzoyloxy or nitrophenylazo groups on Au electrode on quartz crystal substrate using cyclic voltammetry (CV). The Cu(II) ion-sensing film thus prepared was characterized by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The response current of the prepared electrochemical Cu(II) ion sensors was measured by differential pulse voltammetry (DPV). The effects of the substituent on calix[4]arene, sweep cycles and pH of buffer solution on the Cu(II) ion sensing properties (response) of the sensors were investigated to reveal the optimal conditions in the detection of Cu(II) ion in water. The electrochemical Cu(II) ion sensor that was made of the calix[4]arene functionalized with nitrophenylazo groups exhibited a excellent response, good selectivity, acceptable linearity, a low detection limit and favorable long-term stability.