Search results for " pH dependence"

showing 2 items of 2 documents

Luminescence Efficiency of Si/SiO 2 Nanoparticles Produced by Laser Ablation

2019

Photoluminescence properties of Si(core)/SiO 2 (shell) nanoparticles produced by pulsed laser ablation in aqueous solution are investigated with the purpose to highlight the microscopic processes that govern the emission brightness and stability. Time resolved spectra evidence that these systems emit a µs decaying band centered around 1.95 eV, that is associated with the radiative recombination of quantum-confined excitons generated in the Si nanocrystalline core. Both the quantum efficiency and the stability of this emission are strongly dependent on the pH level of the solution, that is changed after the laser ablation is performed. They enhance in acid environment because of the H + pass…

PhotoluminescenceLaser ablationMaterials scienceSi/SiO2 nanoparticles pulsed laser ablation quantum confinement luminescence IR absorption pH dependencebusiness.industry2Surfaces and InterfacesCondensed Matter Physicslaser ablation; pH dependence; photoluminescence; quantum confinement; Si/SiO ; 2; nanoparticlesquantum confinementSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsQuantum dotSio2 nanoparticleslaser ablationMaterials ChemistryPh dependenceOptoelectronicsphotoluminescencenanoparticlespH dependenceElectrical and Electronic EngineeringLuminescencebusinessSi/SiOphysica status solidi (a)
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Voltammetric Investigation on Uranyl Sorption by Alginate Based Material. Influence of Hydrolysis and pH Dependence

2015

The removal of U(VI) as uranyl (UO22+) from aqueous solutions was investigated by sorption onto alginate based material. The hydrolysis of uranyl ion was always taken into account in the calculations of free (22UO) ion in aqueous solution, in the experimental pH range considered, as well as the acid-base properties of alginate polymer. The sorption process follows a pseudo-second order kinetic model and the sorption rate decreases when the pH value increases. In addition to the classical Langmuir and Freundlich models, the equilibrium data were fitted by using a modified multi-component equilibrium model, never tested before. Differential Pulse Voltammetry (DPV) and Inductively Coupled Plas…

U(VI) adsorption; pH dependence; low cost biosorption material; kinetic and equilibrium studies; Differential Pulse Voltammetry; ICP-OES measurementsDifferential Pulse Voltammetrylow cost biosorption materialpH dependencekinetic and equilibrium studieU(VI) adsorptionICP-OES measurements
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