title: Electrochemical response of carbon paste electrode modified with mixture of titanium dioxide/zirconium dioxide in the detection of heavy metals: lead and cadmium.
abstract: A novel carbon modified electrode was developed by incorporating titanium dioxide/zirconium dioxide into the graphite carbon paste electrode to detect heavy metals-cadmium and lead. In this work, the development of the novel titanium dioxide/zirconium dioxide modified carbon paste electrode was studied to determine the optimum synthesis conditions related to the temperature, heating duration, amount and ratio of titanium dioxide/zirconium dioxide, and amount of surfactant, to create the most reproducible results. Using cyclic voltammetric (CV) analysis, this study has proven that the novel titanium dioxide/zirconium dioxide can be utilized to detect heavy metals-lead and cadmium, at relatively low concentrations (7.6×10(-6) M and 1.1×10(-5) M for Pb and Cd, respectively) at optimum pH value (pH=3). From analyzing CV data the optimal electrodes surface area was estimated to be 0.028 (±0.003) cm(2). Also, under the specific experimental conditions, electron transfer coefficients were estimated to be 0.44 and 0.33 along with the heterogeneous electron transfer rate constants of 5.64×10(-3) and 2.42×10(-3) (cm/s) for Pb and Cd, respectively.
authors.affiliation: Environmental Science PhD Program, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435, USA.
authors.forename: Phuong Khanh Quoc
authors.initials: PK
authors.lastname: Nguyen
authors.forename: Suzanne K
authors.initials: SK
authors.lastname: Lunsford
mesh_terms: D002244:Carbon; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000032:analysis*; D014025:Titanium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D019216:Metals, Heavy; C009495:titanium dioxide; D002244:Carbon; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide