Karbondioksidin elektrokimyasal indirgenmesi ve gerçek örneklerde antimon tayini için metal ve/veya metal oksit modifiye polimer ve karbon bazlı kompozit elektrotların geliştirilmesi

Proje no. 628 · Durum: Kapanmış · 2015

Özet

The first of the two main objectives of this project is to develop a modified electrode for carbon dioxide reduction by electrochemical and photoelektrochemical techniques, then to identify structural and chemical surface properties of the developed electrodes, and perform electrochemical and photoelectrochemical applications. For this purpose, metal nanoparticles (Cu and Au) modified polymer film Poly(p-aminophenol) film on glassy carbon electrodes (GCE) were used to investigate the electrochemical reduction of CO2 in different supporting electrolyte (KHCO3, NaClO4 and CH3OH) medium. The highest electrocatalytic activty on CO2 reduction was obtained with Cu/Au modified poly(4-aminophenol) film- coated GCE in 0.8 mol L-1 NaClO4 + 2 mol L-1 CH3OH medium. In the second step of the first objective, the photoelectrochemical reduction of CO2 was investigated. For this purpose, firstly, mesoporous carbon materials (MCM) were synthesized using different carbon initiators such as resorcin, catechol and 4-aminophenol. A new composite material was obtained by mixing with the synthesized MCM and TiO2 obtained by the sol-gel method to increase the photoelectrochemical catalytic activity on CO2 reduction. Photoelectrochemical reduction of CO2 with MCM-TiO2 coated GCE prepared with the appropriate amount of suspension of the composite material was investigated in different supporting electrolyte environments (NaClO4, CH3OH, KHCO3) and a series of optimization studies were carried out to obtain the best photoelectrocatalytic activity. The best photoelectrocatalytic effect was obtained on the GCE electrode prepared with 10 µL MCM-TiO2 suspension, in 0.5 M KHCO3 electrolyte solution. The second aim of the project is to develop a selective and sensitive modified electrode for the determination of Sb(III). In order to investigate the electrochemical behavior of Sb(III) in 0.1 mol L-1 HCl medium, copper(II) phthalocyanine (CuPc) modified poly(cresol red) and overoxidized poly(cresol redox) film GC electrodes were prepared.Among the prepared electrodes, the most sensitive surface to Sb(III) is CuPc/poly(cresol redox)/GCE, and the peak current height with the Sb(III) concentration was found to be linear in the range of 8.0x10-11 – 1.0x10-9 mol L-1 concentration. Detection limit was obtained as 1.18x10-11 mol L-1 (3S/m). The recovery in the sample analysis performed with the developed CuPc/Poly(cresol redox)/GC electrode was obtained in the range of 98.0–103.0%.           After the optimization studies, surface characterizations of metal nanoparticle polymer-modified electrodes and carbon-based material-metal oxide photoelectrocatalyst-modified electrodes prepared under optimum conditions were performed by scanning electron microscopy, energy dispersion x-ray spectroscopy, x-ray photoelectron spectroscopy, and electrochemical impedance technique.

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