Journal of Physical Studies 22(1), Article 1601 [4 pages] (2018) DOI: https://doi.org/10.30970/jps.22.1601 PHOTOCATALYTIC PROPERTIES OF ZINC OXIDE-POROUS SILICON NANOCOMPOSITE PHOTOCATALYST L. Toporovska{1}, B. Turko1, P. Parandiy2, R. Serkiz1, V. Kapustianyk{1,3}, M. Rudko3 1Faculty of Physics, Ivan Franko National University of Lviv, 8, Kyrylo and Mefodiy St., 79005, Lviv, Ukraine 2Faculty of Electronics and Computer Technologies, Ivan Franko National University of Lviv, 50, Drahomanov St., 79005, Lviv, Ukraine 3Scientific-Technical and Educational Centre of Low Temperature Studies, Ivan Franko National University of Lviv, 50, Drahomanov St., 79005, Lviv, Ukraine

Wastewater treatment to remove organic impurities remains the most important task of water resources recovery facilities. A promising method of purification of water from the organic dyes is photocatalysis with semiconductor materials. The most known and popular photoactive materials are based on TiO$_2$, WO$_3$, Zn$_2$SnO$_4$ and ZnO. The catalysts based on ZnO are low cost, stable, non-toxic and do not require reactivation. A composite photocatalyst formed by a layer of ZnO nuclei with $n$-type electric conductivity covered with ZnO nanoflowers with $n$-type electric conductivity and porous silicon with $p$-type electric conductivity has been obtained. The photodegradation of dye in the presence of the composite photocatalysts based on the thin films and nanoflowers was investigated. The photocatalytic properties of ZnO materials were tested using the photocatalytic degradation of an aqueous solution of methyl orange dye serving as a model water contaminant. It has been found that the usage of nanoflowers leads to an improvement in the photocatalytic properties of the composites. An increase of about 30$\%$ in the efficiency of dye photodegradation, when a composite photocatalyst based on ZnO nanoflowers and porous silicon was used instead of a composite photocatalyst based on ZnO film and porous silicon, was found to be due to a larger effective surface area of ZnO nanoflowers. The morphology of the samples was examined using a scanning electron microscope-analyzer.

PACS number(s): 61.82.Rx, 78.55.Et, 78.67.-n, 82.65.+r

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