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Photoactive nanomaterials are of considerable interest to the scientific community for many years and their importance increases with increasing environmental pollution. This study is focused on ZnO/clay photoactive nanocomposites where ZnO nanoparticles are the photoactive components and the clay serves as a cheap and chemically stable matrix on which the ZnO nanoparticles are anchored. Anchoring nanoparticles on the matrix is often used method allowing easier handling of the nanocomposite (clay particles are of micrometric sizes) in comparison with pure nanoparticles. Moreover, nanoparticles anchored on the matrix do not represent such an environmental and healts risks (due to the reduced mobility) as pure nanoparticles. Two clays were used in this study: kaoline KKAF and Moroccan clay ghassoul, unique mixture of stevensite and sepiolite, from Jebel Ghassoul deposit in Morocco. Photoactive nanocomposites were prepared from ZnCl2 and NaOH precursors using a simple hydrothermal method. Resulting samples were dried and calcined at 600 °C for 1 h. The precursors:clay ratios were chosen so that the nanocomposites contained 50 wt.% of ZnO. Nanocomposites were characterized using X-ray powder diffraction, UV-VIS diffuse reflectance spectroscopy, and scanning electron microscopy techniques. Photodegradation activities were evaluated by discoloration of acid orange 7 aqueous solutions under UV irradiation. Sizes of crystallites and band gap energies were determined. Mutual comparison of the properties of both nanocomposites and also the comparison with pure ZnO nanoparticles were carried out.
Keywords: photodegradation activity, ZnO, clay, nanocomposite© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.