Degradation of 2,6-dichlorophenol by Fe-doped TiO₂ Sonophotocatalytic process: kinetic study, intermediate product, degradation pathway

ABSTRACT

TiO₂ and Fe-doped TiO₂ nanoparticles were synthesised by sol-gel method. To determine the properties of nanoparticles, scanning electron microscopy, X-ray diffraction and diffuse reflectance spectroscopy were used. The results of the analysis showed that the synthesised nanoparticles are almost uniform and agglomerated as well as the Fe-TiO2 band gap has decreased from 3.1 to 2.84 and the absorption spectrum has changed towards the visible region. The final concentration of 2,6-dichlorophenol and degradation products were measured with gas chromatography-flame ionisation detector and gas chromatography-mass spectrometry. The maximum efficiency and reaction rate constant of 2,6-dichlorophenol were determined at pH 4 and k₀ = 2.11 × 10⁻², initial concentration of 2,6-dichlorophenol 20 mg L⁻¹ and k₀ = 8.01*10⁻², and nanoparticles dosage of 500 mgL⁻¹ and k₀ = 5.07*10⁻² at 90 min time. The degradation reaction followed the first-order kinetic model. The efficiency of degradation and mineralisation of 2,6-dichlorophenol were in order of sonophotocatalytic > photocatalytic > sonocatalytic.

KEYWORDS:

• Advanced oxidation
• Fe-doped TiO₂
• sonophotocatalytic process
• chlorophenol

Acknowledgements

This research is a part of the approved thesis of Zahedan University of Medical Sciences (Grant number: 8771, Ethics code: IR.ZAUMS.REC.1397.129).The authors would like to thank Zahedan University of Medical Sciences for funding this research.

Disclosure statement

No potential conflict of interest was reported by the author(s).