CHEMISTRY AND MATERIAL SCIENCE

TiO$_2$ nanotubes modified with cadmium oxide for photoelectrocatalytic oxidation of alcohols

V. A. Grinberg, V. V. Emets, A. V. Shapagin, A. A. Averin, A. A. Shiryaev

Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, Russia

Abstract: TiO$_2$ nanotube (TNT) electrodes were fabricated by electrochemical anodization of titanium in ethylene glycol electrolyte with added NH$_4$F (0.5 wt.%) and water (2% w/w). The (TNT)-cadmium oxide (CdO) composite was fabricated using potentiostatic cathodic deposition. Structural properties of the obtained coatings have been investigated by scanning electron microscopy and X-Ray photoelectron spectroscopy, Raman spectroscopy, X-Ray diffraction and transmission electron microscopy. The TNT-CdO electrode demonstrates high efficiency in photoelectrochemical degradation of methanol, ethylene glycol, glycerol and sorbitol in aqueous solutions of 0.1 M Na$_2$SO$_4$ upon irradiation by a simulated sunlight. The highest photooxidation currents were obtained for sorbitol. Intensity-modulated photocurrent spectroscopy shows that the photoelectrocatalysis efficiency is due to suppression of the electron-hole pairs' recombination and to increase in the rate of photo-induced charge transfer. Thus, the TNT-CdO composite is an effective photoanode for developing the technology of photoelectrochemical degradation of sorbitol and other alcohols by-products of biofuel production.

Keywords: nanotubes, TiO$_2$–CdO composite, photoelectrocatalytic oxidation, methanol, ethylene glycol, glycerol, sorbitol.

Received: 21.01.2025
Revised: 06.03.2025
Accepted: 05.05.2025

Language: English

DOI: 10.17586/2220-8054-2025-16-3-352-363

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