PEDOT-Type Conducting Polymers/Black TiO<sub>2</sub> Composites for Electrochemical Determination of Cd<sup>2+</sup> and Pb<sup>2+</sup>
Zongna Yu, Ruxangul Jamal, Ruanye Zhang, Wenli Zhang, Yinqiang Yan, Yingcheng Liu, Yi Ge, Tursun Abdiryim
Abstract
In this paper, the PEDOT-type conducting polymers/black TiO 2 composites were prepared by in situ polymerization method by varying the weight ratio of black TiO 2 to monomer (3,4-ethylenedixoythiophene(EDOT) or 3,4-propylenedixoythiophene (ProDOT)). And, these composites (PEDOT/B-TiO 2 and PProDOT/B-TiO 2 ) were applied for the electrochemical determination of Cd 2+ and Pb 2+ by using differential pulse voltammetry (DPV). The relationship between the structure and electrochemical performances was studied systematically. The structural analysis revealed that the PEDOT-type conducting polymers could act with B-TiO 2 by non-covalent bonding. The combination of polymers with B-TiO 2 effectively enhanced adsorption and charge transfer ability of composites to heavy metal ions, which was favorable for enhancing the eletrcocatalytic ability of composites. The results showed that under optimized conditions, the limit of detection (LOD) of the PEDOT/B-TiO 2 composite electrode from 50 wt% B-TiO 2 are 0.00073 μ M and 0.0816 μ M, respectively, and the linear range of simultaneous detection of Pb 2+ and Cd 2+ is from 0.04 to 1.24 μ M. In the case of PProDOT/B-TiO 2 , the LOD of composite electrode from 50 wt% B-TiO 2 for Pb 2+ are 0.00087 μ M (0.04–0.4 μ M) and 0.00186 μ M (0.4–1.8 μ M), respectively, and the LOD for Cd 2+ are 0.01523 (linear range of 0.04–0.4 μ M) and 0.03214 (linear range of 0.4–1.8 μ M), respectively.