چكيده به لاتين
Semiconductor photocatalysis is an advanced popular oxidation process that is often used in the degradation of organic pollutants. This photocatalysis has been widely used due to its high efficiency, simplicity, good reproducibility, effortless control, and environment-friendly. In this research, porous semiconductor ZnS, ZnO, and porous ZnS-ZnO nanocomposite have been used for photocatalytic removal of methylene blue with LED lamps. ZnS nanoparticles were synthesized by a chemical reaction between zinc precursor [Zn(NO3)2.6H2O] and sulfide [Na2S.5H2O] in an ethanol environment, and porous nanoparticles were obtained by removing NaNO3 by-product as a soft template. These particles were oxidized in the air atmosphere and turned into porous ZnO and porous ZnS-ZnO. Synthesized specimens were characterized using powder X-ray diffraction, N2-physisorption, Simultaneous thermal analysis, High-resolution transmission electron microscopy, photoluminescence spectroscopy, Field emission scanning electron microscopy, Diffuse reflectance spectroscopy, FT-IR spectroscopy, Mott-Schottky technique, and visible-ultraviolet spectroscopy. According to the results, specific surface areas were reported 165m2g-1, 35m2g-1, and 10m2g-1 for ZnS, ZnS-ZnO, and ZnO samples, respectively. The bandgap for these three samples was equal to 3.3eV, 2.8eV, and 2.9eV. The carrier density for ZnS, ZnS-ZnO, and ZnO was calculated 9.211015Cm-3, 1.071016Cm-3, and 2.581015Cm-3. ZnS, despite its higher bandgap and lower charge carrier than ZnS-ZnO, has better photocatalytic efficiency. The specific surface area and the interband states in the ZnS structure affect its higher efficiency. Therefore, the ZnO because of the lowest charge carrier and specific surface areas has the most insufficient activity.
