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Enhanced UV and visible light - driven Photocatalytic degradation of Tartrazine by Nickel-doped Cerium oxide Nanoparticles
摘要： Nickel-doped cerium oxide nanoparticles were synthesized via a simple aqueous coprecipitation method. The synthesized nanoparticles were thoroughly characterized by PXRD, TEM, SEM, EDX, Raman, and UV-Vis spectroscopic techniques. XRD study confirmed the doping of nickel in the cerium oxide lattice. The shift in Raman spectra revealed the formation of nanoparticles in their pure phase with fluorite structure. EDX revealed the formation of a solid solution on doping Ni- to CeO2. SEM images revealed considerable agglomeration. TEM analysis asserted the average particle size of 8-10 nm with a well-defined spherical shape. The particle size was found to be sensitive to dopant concentration, i.e., it decreased with increase in the concentration of the dopant. A comparative UV-visible spectroscopic analysis showed the remarkable red shift in the band gap of nickel-doped cerium oxide nanoparticles. Investigation of photocatalytic activity towards degradation of azo dye tartrazine showed that 3 mol% and 5 mol% Ni- CeO2 nanoparticles exhibited 53.4% and 63.7% photodegradation respectively under visible irradiation while 57.4% and 65.4% respectively under UV irradiation. The study suggests that the band gap of cerium oxide nanoparticles can be easily tuned (decreased) by doping of nickel at different concentrations. The observed improved photocatalytic activity upon Nickel doping is attributed to the narrow band gap.
关键词： azo dye,mechanism,tartrazine,photocatalysis,Nickel-doped cerium oxide nanoparticles
更新于2025-09-23 15:21:01
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Preparation of Cerium Oxide Nanoparticles in Salvia Macrosiphon Boiss seeds Extract and Investigation of Their Photo-catalytic Activities
摘要： Cerium oxide nanoparticles (CNPs) with desired particle size and spherical morphology were prepared from cerium nitrate in bio media of Salvia macrosiphon Boiss seeds extract, as a green synthesis route. Then they were characterized by XRD, UV-Vis and FTIR spectroscopies, FESEM and TGA. Band gap energy of the prepared powders was also determined which was found in the range of 2.5 to 3.5 eV. Determination of DLS and zeta potential were showed that CNPs had small size and unique colloidal stability, respectively. Then the photo-catalytic activity of them was investigated by degradation of Rhodamine B (RhB) dye as a model of waste water pollutants, under UV-irradiation and optimum conditions were evaluated. Results showed that decreasing the particle size increased the rate of photo-catalytic reaction remarkably but ascending the band gap energy, in contrast. The photo-catalytic mechanism was also studied by using different scavengers.
关键词： Rhodamine B,Cerium Oxide nanoparticles,Dye,Green synthesis,Photo-degradation,Salvia seeds extract
更新于2025-09-10 09:29:36
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Ionic Radii and Concentration Dependency of RE <sup>3+</sup> (Eu <sup>3+</sup> , Nd <sup>3+</sup> , Pr <sup>3+</sup> and La <sup>3+</sup> ) Doped Cerium Oxide Nanoparticles for Enhanced Multi-Enzyme Mimetic and Hydroxyl Radical Scavenging Activity
摘要： The anti-oxidant activity of cerium oxide nanoparticles (CNPs) depends on the concentration of oxygen vacancies and Ce3+ active sites. In the present work, we report the impact of 5 mol% tri-valent rare earth doped (RE3+ = Eu3+, Nd3+, Pr3+ and La3+) CNPs on the oxidation state modulation and anti-oxidant property with respect to ionic radii. An increase in lattice parameter, strain and oxygen vacancy concentration was observed as a function of ionic radii. Among the various dopants in CNP, La3+ with higher ionic radii having smaller crystallite size (7.9 nm) and higher vacancy displayed better peroxidase, oxidase and hydroxyl radical (HO?) scavenging activity. The kinetic parameters for the peroxidase and oxidase activity was found to be superior with Km = 0.217 mM and 0.261 mM, respectively, for 5 mol% La3+ doped CNPs. In order to divulge the role of dopants concentration on structural properties, we also explored using 10 and 20 mol% La3+ doping in CNP. Due to smaller crystallite size (6.7 nm) and higher defect level (3.12 x 1021 cm-3), 20% La3+ doping showed superior peroxidase and oxidase activity as shown by the low Km values. CNPs exhibit both peroxidase and oxidase activity in a concentration dependent manner. Moreover, CNPs exhibit a concentration dependent peroxidase and oxidase activity that can be selectively activated for various theranostic applications. Thus, our results demonstrate the crucial role of ionic radii and concentration of RE3+ dopants on the defect formation in cerium oxide nanoparticles for improved anti-oxidant properties of ceria.
关键词： ionic radii,RE3+ doping,oxygen vacancies,peroxidase activity,oxidase activity,hydroxyl radical scavenging,cerium oxide nanoparticles,anti-oxidant properties
更新于2025-09-04 15:30:14