Journal of Physical Studies 24(3), Article 3701 [5 pages] (2020) DOI: https://doi.org/10.30970/jps.24.3701 ZnO MICRORODS AS AN EFFECTIVE MATERIAL FOR PHOTOELECTROCATALYTIC WATER PURIFICATION L. Toporovska{1*} , B. Turko{1} , V. Kapustianyk{1,2} , M. Rudko{1,2} , R. Serkiz{1}  1Department for Solid State Physics, Ivan Franko National University of Lviv, 50, Drahomanov St., Lviv, UA-79005, Ukraine 2Scientific-technical and Educational Centre of Low Temperature Studies, Ivan Franko National University of Lviv, 50, Drahomanov St., Lviv, UA-79005, Ukraine Received 29 December 2019; in final form 11 June 2020; accepted 18 June 2020; published online 03 September 2020

A microcomposite catalyst based on zinc oxide microstructures and silicon was synthesized for heterogeneous catalysis. ZnO microstructures with elements 6 $ μ$m in diameter, 15 $μ$m long, were grown on conductive silicon (001) substrates by the vapor phase method. Methyl orange (C$_{14}$H$_{14}$N$_3$NaO$_3$S) was selected as an organic dye for testing the photocatalytic and photoelectrocatalytic properties of ZnO microstructures. The sample was placed in an aqueous solution of methyl orange in order to perform a photocatalytic decomposition of the dye. DRT-125 quartz lamp with a radiation power of no more than 26 W was used as the radiation source in the wavelength range from 315 to 400 nm. The sample with the aqueous solution of dye in a standard 3.5 ml quartz quvet was irradiated with the lamp at a distance of 10 cm from it. In order to perform the photoelectrocatalytic decomposition of the dye in the aqueous solution, an electric field of 1.5 V was applied between ZnO/Si and Al electrodes, that were simultaneously irradiated with UV for 5 cycles lasting 20 minutes (100 minutes).

The degradation kinetics of the dye was determined by changing its concentration, on the basis of the optical density measurement at the absorption maximum of the dye (465 nm) using a Specord M 40 spectrometer. During the photocatalysis, the concentration of the dye decreased by 41 \

Key words: ZnO microrods, photodegradation, photoelectrocatalysis, absorption spectroscopy.

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