Aishwarya Singh; bhavani prasad nenavathu
Abstract
Mg(OH)2/CdS heteronanostructures have been successfully synthesized by a novel precipitation method and the synthesis involves three steps. The first step involves the synthesis of Mg (OH)2nanoparticles using homogeneous precipitation method. Then, surface-modifying agent citric acid was used to functionalise ...
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Mg(OH)2/CdS heteronanostructures have been successfully synthesized by a novel precipitation method and the synthesis involves three steps. The first step involves the synthesis of Mg (OH)2nanoparticles using homogeneous precipitation method. Then, surface-modifying agent citric acid was used to functionalise Mg (OH)2. Finally, the cadmium sulfide (CdS) shell was deposited on the surface modified Mg (OH)2by co-precipitation method. The Mg(OH)2/CdS heteronanostructures were characterized using X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy. DRS results showed blue shift of CdS band gap absorption with respect to bulk CdS. XPS results showed evidence for the binding energies of Mg(OH)2, Cd and S. The Mg (OH)2/CdS heteronanostructures was explored as catalyst for sunlight induced photocatalytic degradation of β- naphthol pollutant. The batch of 0.2 mg/ mL of Mg (OH)2/CdS heteronanostructures maintained at pH 8.5 showed maximum photodegradation efficiency (75 ± 2.1 %). Higher photocatalytic degradation efficiency for Mg(OH)2/CdS heteronanostructures could be due to incorporation of CdS and increased reactive oxygen species (ROS) generation. The reusability of the Mg (OH)2/CdS heteronanostructures was also tested, and they show stability for up to three cycles without loss of efficiency.
Bhavani Nenavathu; Aarti Sharma; Raj Kumar Dutta
Abstract
Pristine and Se doped ZnO nanoparticles (NPs) were successfully synthesized by thermo-mechanical method and their structural, morphological and optical properties are characterized. Here in, a series of experiments were carried out where cholesterol is treated with same concentration of Pristine as well ...
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Pristine and Se doped ZnO nanoparticles (NPs) were successfully synthesized by thermo-mechanical method and their structural, morphological and optical properties are characterized. Here in, a series of experiments were carried out where cholesterol is treated with same concentration of Pristine as well as Se doped ZnO NPs. Several Cholesterol oxidation products (COP’s) such as 25-hydroxycholesterol and 26-hydroxycholesterol, 7α-hydroxycholesterol, 7β-hydroxycholesterol, 7-ketocholesterol are formed as observed by HPLC analysis. The batch of 5 wt % Se doped ZnO NPs exhibited highest cholesterol degradation efficiency followed by pristine ZnO NPs and 2 wt % Se doped ZnO NPs. The peak area corresponding to 7-ketocholesterol and 25-hydroxycholesterol is found to be 200980 AU and 200986 AU respectively. The mechanism of cholesterol degradation was correlated with incorporation of oxygen vacancies due to Se doping, which were likely intermediate levels for transiting photoexcited charge carriers for generation of hydroxyl radicals. Further, hydroxyl radicals generated during interaction of ZnO nanoparticles with aqueous media have been determined using terephthallic acid assay and 2′, 7′-di-chlorofluorescein (DCF) assay.