الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Water pollution considers one of the most factors that influencing the decrease in the quantities of drinking water from its sources. Scientists were interested to use several methods to eliminate the organic pollutants from the wastewater using semiconductor photocatalysts which considers the most important techniques that are used for purification of water, especially industrial wastewater from persistent organic pollutants and other because they are more efficient, eco and environment-friendly. In the present study, we prepared CuS nanoparticles and rGO/CuS nanocomposites, which show absorption in the visible light region. The photocatalytic activity of the prepared samples was studied on the degradation of Malachite green dye (one of textile dyeing). The CuS nanoparticles are prepared by precipitation method with different parameters to prepare pure hexagonal CuS and rGO/CuS nanocomposites (3, 5, 7, 10 and 12% rGO) are prepared through in-situ method. After that, characterized by various techniques such as XRD, FTIR, Raman spectroscopy, XPS, SEM, EDX, TEM, BET surface Area, UV-Vis DRS and PL. The extent of photocatalytic degradation was tested using UV–Visible spectrophotometer and mineralization were examined by measuring TOC in solution. The CuS photocatalyst achieved 95.5% at pH 5 by using 500 mg/L of CuS at 10 ppm of MG under direct sunlight after 90 min. And also, the 7% rGO/CuS nanocomposite is achieved a higher efficiency 97.6% at pH 5 by using 300 mg/L at 10 ppm of MG under direct sunlight after 90 min. The reusability of CuS and 7% rGO/CuS photocatalysts were also checked and confirmed their stability of photocatalytic activity. Moreover, the reaction kinetics of CuS and 7% rGO/CuS photocatalysts were followed using the pseudo-first-order model. Finally, the mineralization was studied by using TOC analysis, where 7% rGO/CuS achieved 76.06 % mineralization of MG at pH 5 by using 300 mg/L after 90 min.