Comparison of Two Types of Overoxidized PEDOT Films and Their Application in Sensor Fabrication.
Poly(3,4-ethylenedioxythiophene) (PEDOT) films were prepared by electro-oxidation on Au microelectrodes in an aqueous solution. Electrolyte solutions and polymerization parameters were optimized prior to overoxidation. The effect of overoxidation time has been optimized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), which results in the film overoxidized for 45 s at 1.35 V presenting a strong adsorption. The other one-step overoxidation film prepared by direct CV ranging from -0.6 V to 1.35 V was polymerized for comparison. Scanning electron microscope (SEM) analysis and Fourier transform infrared (FTIR) spectroscopy were used for monitoring morphological changes and the evolution of functional groups. Both of them indicate increased abundant oxygen functional groups and roughness, yet the products exhibit dendritic morphology and piles of spherical protrusions, respectively. Moreover, double-step overoxidized film showed better electrochemical performance toward lead ion sensing. These characterizations highlight some novel properties that may be beneficial for specific sensing applications.
State Key Laboratory of Transducer Technology, Institute of Electronics Chinese Academy of Sciences, Beijing 100190, China. huiyunccc@126.com.|School of Electronic, Electrical, and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100190, China. huiyunccc@126.com.
Yun
Y
Hui
State Key Laboratory of Transducer Technology, Institute of Electronics Chinese Academy of Sciences, Beijing 100190, China. cbian@mail.ie.ac.cn.
Chao
C
Bian
CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China. wangjinfen@nanoctr.cn.
Jinfen
J
Wang
State Key Laboratory of Transducer Technology, Institute of Electronics Chinese Academy of Sciences, Beijing 100190, China. jhtong@mail.ie.ac.cn.
Jianhua
J
Tong
State Key Laboratory of Transducer Technology, Institute of Electronics Chinese Academy of Sciences, Beijing 100190, China. shxia@mail.ie.ac.cn.
Shanhong
S
Xia
Au microelectrode; EIS; FTIR; SEM; overoxidized PEDOT; oxygenic functional groups; roughness