Structural and spectroscopic investigation of ZnS nanoparticles grown in quaternary reverse micelles

Manyar, Haresh; Iliade, Patrizia; Bertinetti, Luca; Coluccia, Salvatore; Berlier, Gloria

doi:10.1016/j.jcis.2010.11.033

Cited by 19 publications

(11 citation statements)

References 47 publications

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“…Photocatalytic oxidation of phenolics utilizing UV is affected by solution concentration, pH, quantity, morphology and nature of the metal oxides present in the catalyst [9][10][11][12]. Besides, these factors, the reactor design must be optimized in order to assure complete degradation of organics [13].…”

Section: Introductionmentioning

confidence: 99%

Batch to continuous photocatalytic degradation of phenol using TiO2 and Au-Pd nanoparticles supported on TiO2

Yilleng

Gimba

Ndukwe

et al. 2018

Journal of Environmental Chemical Engineering

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A series of Au-Pd/TiO2 catalysts were synthesized in different weight % using sol-immobilization method. Of the range studied 1%Pd/TiO2 catalyst achieved 86.4% conversion of phenol to CO2 in a standard batch-slurry system utilizing UV. However under recycle or continuous operation Pd leaching from catalyst surface led to gradual deactivation. Au-Pd nanoparticles supported on TiO2 P25 were stable and recyclable, here Au species were found to help to anchor Pd species on TiO2, and no observable Pd leaching occurred. Utilizing UV, 1%Pd/TiO2 showed faster rate of phenol degradation in comparison to Au-Pd/TiO2, while 1%Au/TiO2 and 0.5%Au-0.5%Pd/TiO2 showed faster phenol degradation rates under visible light. The TiO2 P25 support was also found to be active, stable and recyclable in phenol degradation utilizing UV; and was hence considered suitable for continuous operation. However poor oxygen mass transfer led to the formation and lay-down of polymeric species when using a Trickle bed approach. Operation in the Taylor flow regime was demonstrated to increase oxygen saturation and significantly reduced deactivation. Hence continuous photocatalytic degradation of phenol could be achieved using TiO2 under Taylor Flow conditions.

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Section: Introductionmentioning

confidence: 99%

Batch to continuous photocatalytic degradation of phenol using TiO2 and Au-Pd nanoparticles supported on TiO2

Yilleng

Gimba

Ndukwe

et al. 2018

Journal of Environmental Chemical Engineering

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“…The measured intensities were converted with the Kubelka-Munk function. The fundamental absorption, which corresponds to electron excitation from the valance band to conduction band, can be used to determine the value of the optical band gap of the synthesized ZnS nanoparticles [34][35][36][37]. The relation between the incident photon energy (hm) and the absorption coefficient (a) is given by the following relation: (ahm) 1/n = A(hm À E g ), where A is constant and E g is the band gap energy of the material and the exponent n depends on the type of transition [38,39].…”

Section: Characterizationmentioning

confidence: 99%

“…This parameter is quite important for applications in photocatalysis, and in semiconducting materials is dependent on particle size, due to quantum size effect [34-37, 40, 63]. Notwithstanding the small size of the primary ZnS NP prepared in this work, these cannot be defined as Quantum Dots (QD), since the UV-Vis spectra of the latter are characterized by the presence of discrete bands (described by the position of their maximum) instead of a continuum absorption (defined by its edge position) [37]. The spectrum of as prepared ZnS_6h is characterized by a relatively large E g value (4.22 eV, Tab.…”

Section: Electronic Propertiesmentioning

confidence: 99%

Effect of Post-Synthesis Treatments on the Properties of ZnS Nanoparticles: An Experimental and Computational Study

Balantseva

Camino

Ferrari

et al. 2015

Oil Gas Sci. Technol. – Rev. IFP Energies nouvelles

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-This work deals with the characterization of ZnS NanoParticles (NP), prepared by precipitation employing thioacetamide as sulfur source at different reaction time length. The attention is focused on the modification induced on structural, surface and electronic properties of ZnS NP by post-synthesis treatments. These were aimed at removing from the samples surface adsorbed reactants, by washing or thermal treatments, both in air or vacuum. The effect of these parameters is followed by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Fourier Transform InfraRed (FTIR), gas-volumetric and ThermoGravimetric Analysis (TGA). Moreover, the effect of nanostructuration on the semiconducting material band gap is evaluated by Diffuse Reflectance UV-Vis (DR UV-Vis) spectroscopy. Density Functional Theory (DFT) calculations have been employed to clarify the role of the adsorbed reactants on the surface stability and to assess the relationship between particle size and band gap value.Résumé -Effet des traitements après-synthèse sur les propriétés de nanoparticules de ZnS : une étude expérimentale et computationnelle -Ce travail concerne la caractérisation de nanoparticules de ZnS préparées par précipitation en présence de ThioAcétAmide (TAA) comme source de soufre. On a étudié, en particulier, les modifications des propriétés structurelles, superficielles et électroniques en fonction des paramètres de synthèse (temps, solvant et source de soufre) et des traitements après-synthèse considérés. Ces derniers avaient pour but d'éliminer les réactifs adsorbés sur la surface par lavages ou traitements thermiques à l'air ou sous vide. L'effet des différents traitements a été suivi par diffraction des rayons X (XRD), microscopie de transmission électronique (TEM), spectroscopie infra rouge à transformée de Fourier (FTIR), analyse volumétrique des gaz et thermogravimétrie (TGA). En outre, l'effet de la nanostructure sur les propriétés de la largeur de bande du matériau semi-conducteur a été évalué par spectroscopie de reflectance UV-Vis (DR UV-Vis). Des théories de la fonctionnelle de la densité (DFT) ont été utilisées pour clarifier le rôle des réactifs adsorbés sur la stabilité de la surface et pour établir une relation entre la dimension des particules et la largeur de bande.

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“…Chen et al suggested pentanol was a ‘superior’ co‐surfactant and attributed the differences in nanoparticle synthesis to the stronger van der Waals interaction between pentanol and CTAB, which they concluded lead to a more compact and stable interface. However, an investigation of ZnS nanoparticles formed in CTAB/hexane/ n ‐alkanol/water RMs found no significant differences in the size or size distribution of nanoparticles formed with either butanol or pentanol co‐surfactants. Yet, in an investigation of the effects on copper oxalate nanoparticle synthesis for a range of alcohol co‐surfactants, from 1‐butanol to 1‐decanol, by Ganguli et al , the chain length of the co‐surfactant was found to have an influence on the dimensions of the nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

NMR study of the influence of n‐alkanol co‐surfactants on reverse micelles in quaternary microemulsions of cetyltrimethylammonium bromide (CTAB)

Mills

Britton

2016

Magnetic Reson in Chemistry

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The effects of different n-alkanol co-surfactants on the size, shape, composition and dynamics of reverse micelles (RMs) in cetyltrimethylammonium bromide (CTAB)/n-alkanol/n-hexane/water and CTAB/n-alkanol/n-pentane/water microemulsions were investigated using T relaxation and pulsed gradient stimulated echo nuclear magnetic resonance (NMR) measurements and molecular modelling. NMR T relaxation times and diffusion coefficients were determined for the surfactant and co-surfactant in these CTAB quaternary reverse microemulsions, for a range of medium chain length alcohol co-surfactants, from 1-butanol to 1-heptanol. These data revealed a slight RM size dependency on co-surfactant chain length, with RM sizes tending to decrease with increasing alcohol chain length. Molecular modelling of CTAB/n-alkanol/n-hexane/water RMs suggested a variation in RM shape with co-surfactant chain length, where those formed with pentanol were found to be least spherical and those formed with heptanol the most spherical. The NMR data also revealed differences in the behaviour of the micellar structures in the CTAB/n-pentanol/n-hexane/water reverse microemulsion, compared with the other reverse microemulsions in this study, where CTAB was found to be distributed between two environments, which then combined to form larger micelles. The origins of these differences remain unclear. Copyright © 2016 John Wiley & Sons, Ltd.

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Structural and spectroscopic investigation of ZnS nanoparticles grown in quaternary reverse micelles

Cited by 19 publications

References 47 publications

Batch to continuous photocatalytic degradation of phenol using TiO2 and Au-Pd nanoparticles supported on TiO2

Batch to continuous photocatalytic degradation of phenol using TiO2 and Au-Pd nanoparticles supported on TiO2

Effect of Post-Synthesis Treatments on the Properties of ZnS Nanoparticles: An Experimental and Computational Study

NMR study of the influence of n‐alkanol co‐surfactants on reverse micelles in quaternary microemulsions of cetyltrimethylammonium bromide (CTAB)

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