University of Tabriz

About: University of Tabriz is a education organization based out in Tabriz, Iran. It is known for research contribution in the topics: Population & Nanocomposite. The organization has 12141 authors who have published 20976 publications receiving 313982 citations.

Combined heterogeneous and homogeneous photodegradation of a dye using immobilized TiO2 nanophotocatalyst and modified graphite electrode with carbon nanotubes

Abstract: In this paper, the efficiency of photoelectro-Fenton (PEF) combined with photocatalytic process was studied for decolorization of C.I. Acid Yellow 36 (AY36) as a model textile dye. The investigated photocatalyst was TiO 2 nanoparticles (Degussa P25) immobilized on glass plates. The efficiency of three cathode materials (i.e. bare graphite, activated carbon immobilized onto graphite surface (AC/graphite) and carbon nanotubes immobilized onto graphite surface (CNT/graphite)) was investigated for H 2 O 2 electrogeneration and dye removal. The CNT/graphite electrode fed with air had the best efficiency for H 2 O 2 production and decolorization of AY36 solution. A comparison of electro-Fenton (EF), UV/TiO 2 , PEF, photolysis and PEF/TiO 2 processes for dye removal was performed. Results showed that decolorization followed the decreasing order: PEF/TiO 2 > PEF > EF > UV/TiO 2 > photolysis. Central composite design (CCD) was employed to model and optimize the decolorization of dye solution using combined process. The variables for CCD optimization were initial concentration of Fe (III) and dye, reaction time and applied current. Analysis of variance (ANOVA) showed high coefficient of determination value ( R 2 = 0.9867 and adjusted- R 2 = 0.9751). The degradation pathway of AY36 was proposed based on the identified compounds by GC–Mass technique. The unit energy demand (UED) and operating cost for photoelectrocatalytic process was evaluated.

Electrocatalytic oxidation of hydrazine at cobalt hexacyanoferrate- modified glassy carbon, Pt and Au electrodes

Abstract: The electrocatalytic oxidation of hydrazine has been studied on glassy carbon, Pt and Au electrodes modified by cobalt hexacyanoferrate (CoHCF) using cyclic voltammetry and rotating disc techniques. It has been shown that the oxidation of hydrazine to nitrogen occurs at the potential coinciding with that of Co(II) to Co(III) transformation in a CoHCF film, where no oxidation signal is observed at a bare glassy carbon electrode. A Tafel plot, derived from RDE voltammograms, exhibits a slope of 150 mV, indicating a one-electron charge transfer process to be the rate-limiting step. The electrocatalytic efficiency of the modified electrode towards hydrazine oxidation depends on solution pH, and the optimum range was found to be located between pH 5 and pH 7. The kinetic behaviour and location of the electrocatalytic process were examined using the W.J. Albery diagnosis table, and it was concluded that the reaction has either a “surface” or a “layer” reaction mechanism. Pt- and Au-CoHCF-modified electrodes show no significant electrocatalytic activity towards hydrazine oxidation.