Browsing by Author "Lee, Gang-Juan"

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    High response CO sensor based on a polyaniline/SnO2 nanocomposite
    (MDPI AG, 2019-01-21) Jian, Kai-Syuan; Chang, Chi-Jung; Chang, Yu-Cheng; Tsay, Chien-Yie; Chen, Jing-Heng; Horng, Tzyy-Leng; Lee, Gang-Juan; Karuppasamy, Lakshmanan; Anandan, Sambandam; Chen, Chin-Yi
    A polyaniline (PANI)/tin oxide (SnO2) composite for a CO sensor was fabricated using a composite film composed of SnO2 nanoparticles and PANI deposition in the present study. Tin oxide nanoparticles were synthesized by the sol-gel method. The SnO2 nanoparticles provided a high surface area to significantly enhance the response to the change in CO concentration at low operating temperature (< 75 °C). The excellent sensor response was mainly attributed to the relatively good properties of PANI in the redox reaction during sensing, which produced a great resistance difference between the air and CO gas at low operating temperature. Therefore, the combination of n-type SnO2 nanoparticles with a high surface area and a thick film of conductive PANI is an effective strategy to design a high-performance CO gas sensor. © 2018 by the authors.
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    The design of ZnO nanorod arrays coated with MnOx for high electrochemical stability of a pseudocapacitor electrod
    (MDPI AG, 2023-03-06) Chen, Hsiang-Chun; Lyu, Yang-Ru; Fang, Alex; Lee, Gang-Juan; Karuppasamy, Lakshmanan; Wu, Jerry J; Lin, Chung-Kwei; Anandan, Sambandam; Chen, Chin-Yi
    Tremendous efforts have been made on the development of unique electrochemical capacitors or pseudocapacitors due to the overgrowing electrical energy demand. Here, the authors report a new and simple strategy for fabricating hybrid MnOx-coated ZnO nanorod arrays. First, the vertically aligned ZnO nanorods were prepared by chemical bath deposition (CBD) as a template providing a large surface area for active material deposition. The manganese oxide was subsequently coated onto the surface of the ZnO nanorods to form a hybrid MnOx-coated ZnO nanostructure by anodic deposition in a manganese acetate (MnA)-containing aqueous solution. The hybrid structure of MnOx-coated ZnO nanorod arrays exhibits a large surface area and high conductivity, essential for enhancing the faradaic processes across the interface and improving redox reactions at active MnOx sites. A certain concentration of the deposition solution was selected for the MnOx coating, which was studied as a function of deposition time. Cyclic voltammetry (CV) curves showed that the specific capacitance (SC) of the MnOx-coated ZnO nanostructure was 222 F/g for the deposition times at 10 s when the concentration of MnA solution was 0.25 M. The unique hybrid nanostructures also exhibit excellent cycling stability with >97.5% capacitance retention after 1200 CV cycles. The proposed simple and cost-effective method of fabricating hybrid nanostructures may pave the way for mass production of future intelligent and efficient electrochemical energy storage devices. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.