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Nicola Bazzanella

Bio: Nicola Bazzanella is an academic researcher from University of Trento. The author has contributed to research in topics: Desorption & Pulsed laser deposition. The author has an hindex of 21, co-authored 71 publications receiving 1312 citations.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the performance of Co 3 O 4 NPs assembled coatings has been compared by looking at their efficiency on degradation of methylene blue dye that occurs via photo Fenton reaction in presence of H 2 O 2 or oxone oxidants.
Abstract: Co 3 O 4 nanoparticles assembled coatings have been synthesized by physical (pulsed laser deposition (PLD) and electron beam deposition) and chemical (sol–gel and electroless) techniques. The morphological, structural, and optical properties of all the coatings were analyzed by SEM, XRD, Raman spectroscopy, XPS, and UV–vis spectroscopy. The catalytic activities of the several Co 3 O 4 heterogeneous catalyst coatings have been compared by looking at their efficiency on degradation of methylene blue dye that occurs via photo Fenton reaction in presence of H 2 O 2 or oxone oxidants. The coating synthesized by PLD exhibits the best photo-degradation rate of dye in presence of H 2 O 2 (4 h) or oxone (8 min). The NPs produced by PLD process exhibit smaller average size (18 nm), narrow size distribution ( σ = 3 nm), perfect spherical shape, low degree of agglomeration, and mixed amorphous-nanocrystalline phase. These special features of NPs, along with better visible light absorption, are the main factors responsible for the enhanced photocatalytic activity of the PLD Co 3 O 4 NPs assembled coating. It is also observed that although the concentration of oxone (0.5 mM) was very small as compared to H 2 O 2 (100 mM) the photo-degradation of MB dye solution is much faster for oxone.

115 citations

Journal ArticleDOI
TL;DR: In this article, the performance of Co3O4 NPs assembled thin coating catalyst was compared with homogenous catalyst producing Co+2 ions in methylene blue solution under visible light irradiation, and the effect of H2O2 concentration and effect of pH variation on dye degradation rate has been reported.
Abstract: Cobalt oxide (Co3O4) nanoparticles (NPs) assembled coating have been prepared by reactive pulsed laser deposition of Co, in O2 atmosphere, on Si or glass substrate ranging from room temperature to 250 °C The NPs, having narrow size distribution with average values of around 25–50 nm, were characterized by Raman, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy The Co3O4 NPs synthesized at 150 °C comprise a mixed amorphous–nanocrystalline phase (that is unique property for catalysis) while complete crystallization of Co3O4 occurs at 250 °C with formation of spinel structure Photocatalytic properties of Co3O4 NPs assembled coating for degradation of methylene blue solution under visible light irradiation are reported The effect of H2O2 concentration and effect of pH variation on dye degradation rate has been reported The reusability of the Co3O4 NPs assembled thin coating catalyst was further evaluated in several recycling runs The activity of heterogeneous Co3O4 NPs assembled thin coating catalyst was compared with homogenous catalyst producing Co+2 ions in methylene blue solution

97 citations

Journal ArticleDOI
TL;DR: In this paper, a first approximation of the depletion layer sensing mechanism is used to explain how the geometrical factors of one and two-dimensional nanostructures affect their sensing parameters.
Abstract: In this work we have grown one-dimensional (1D) and two-dimensional (2D) zinc oxide nanostructures. Changing the deposition parameters we were able to obtain ZnO nanowires with an average diameter of 80–250 nm. Nanosheets grown in different conditions show thickness values in the range 70–360 nm. These kinds of nanostructure have been used to fabricate conductometric gas sensors for liquid petroleum gas (LPG) detection. Different sensing parameters are investigated in both cases as a function of the dimensionality and size of the zinc oxide nanostructures. A first approximation of the “depletion layer sensing mechanism” is used to explain how the geometrical factors of one- and two-dimensional nanostructures affect their sensing parameters. The depletion layer affects two dimensions of nanowires and only one of nanosheets. This greatly improves the sensor response of 1D-nanostructures. On the other side two-dimensional nanostructures have a larger cross-section, which increases the base current, thus lowering the limit of detection. At the same operative conditions, nanowires show a better percentage response when compared to similar thickness nanosheets, but 2D nanosheets demonstrate an improved limit of detection (LoD).

79 citations

Journal ArticleDOI
TL;DR: In this paper, a porous coating assembled with hierarchical 3D Co3O4 urchin-like particles was synthesized by Pulsed Laser Deposition (PLD) and thermal oxidation.
Abstract: A porous coating assembled with hierarchical 3D Co3O4 urchin-like particles was synthesized by Pulsed Laser Deposition (PLD) and thermal oxidation. Laser ablation of Co B powder, used as the target material, in oxygen atmosphere formed core–shell particles on the coating surface with mainly a metallic Co core and a mixture of Co, B and O accommodating the shell. The thermal oxidation of these core–shell particles in air at 600 °C induces the morphological transformation to urchin-like particles consisting of nanowires (NWs) (diameter: 30–60 nm and length 1–3 μm) grown radially from the core surface. The extrusion marks on the surface of NWs indicate that the stress induced growth process is caused by difference in the thermal expansion coefficient. XRD, Raman, EXAFS and HRTEM analysis confirmed that the NWs are polycrystalline consisting of pure Co3O4 phase. A wet-chemistry hydrothermal procedure was also employed to synthesize nanostructured urchin-like particles which are hollow and the structure is held together by the radially oriented nanorods (diameter: 40–150 nm). During photocatalysis, urchin-like particles synthesized by PLD displayed significantly higher (∼5 times) degradation rates when compared to chemical urchins for degradation of methylene blue dye via a photo-Fenton reaction in presence of H2O2 and visible light. This is mainly attributed to poor stability of the nanorods in the chemical urchin structure. Features such as high surface area, enhanced stability against agglomeration, polycrystalline nature of the NWs, porous surface and superior adhesion, are responsible for the enhanced photocatalytic activity of Co3O4 urchin-like particles assembled in a porous coating synthesized by PLD and thermal oxidation. Reusability tests also demonstrate the robust nature of the catalyst coating.

73 citations

Journal ArticleDOI
TL;DR: Rare earth-activated 1-D photonic crystals were fabricated by RF-sputtering technique and confirm the presence of a stop band from 1500 nm to 2000 nm with a cavity resonance centered at 1749 nm at 0° and a quality factor of 890.
Abstract: Rare earth-activated 1-D photonic crystals were fabricated by RF-sputtering technique. The cavity is constituted by an Er3+-doped SiO2 active layer inserted between two Bragg reflectors consisting of ten pairs of SiO2/TiO2 layers. Scanning electron microscopy is employed to put in evidence the quality of the sample, the homogeneities of the layers thickness and the good adhesion among them. Near infrared transmittance and variable angle reflectance spectra confirm the presence of a stop band from 1500 nm to 2000 nm with a cavity resonance centered at 1749 nm at 0° and a quality factor of 890. The influence of the cavity on the 4I13/2 → 4I15/2 emission band of Er3+ ion is also demonstrated.

71 citations


Cited by
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Proceedings Article
01 Jan 1972
TL;DR: In this paper, the main theoretical and experimental developments to date in Integrated Optics are reviewed, including material considerations, guiding mechanisms, modulation, coupling and mode losses, as well as the fabrication and applications of periodic thin film structures.
Abstract: In order to enable optical systems to operate with a high degree of compactness and reliability it is necessary to combine large number of optical functions in small monolithic structures. A development, somewhat reminiscent of that that took place in Integrated Electronics, is now beginning to take place in optics. The initial challenge in this emerging field, known appropriately as "Integrated Optics", is to demonstrate the possibility of performing basic optical functions such as light generation, coupling, modulation, and guiding in Integrated Optical configurations. The talk will review the main theoretical and experimental developments to date in Integrated Optics. Specific topics to be discussed include: Material considerations, guiding mechanisms, modulation, coupling and mode losses. The fabrication and applications of periodic thin film structures will be discussed.

786 citations

Journal Article
01 Jan 2008-Nature
TL;DR: It is shown that bright fluorescent nanodiamonds can be produced in large quantities by irradiating synthetic diamond nanocrystallites with helium ions, and the fluorescence is sufficiently bright and stable to allow three-dimensional tracking of a single particle within the cell by means of either one- or two-photon-excited fluorescence microscopy.
Abstract: Fluorescent nanodiamond is a new nanomaterial that possesses several useful properties, including good biocompatibility1, excellent photostability1,2 and facile surface functionalizability2,3. Moreover, when excited by a laser, defect centres within the nanodiamond emit photons that are capable of penetrating tissue, making them well suited for biological imaging applications1,2,4. Here, we show that bright fluorescent nanodiamonds can be produced in large quantities by irradiating synthetic diamond nanocrystallites with helium ions. The fluorescence is sufficiently bright and stable to allow three-dimensional tracking of a single particle within the cell by means of either one- or two-photon-excited fluorescence microscopy. The excellent photophysical characteristics are maintained for particles as small as 25 nm, suggesting that fluorescent nanodiamond is an ideal probe for long-term tracking and imaging in vivo, with good temporal and spatial resolution.

643 citations

Journal ArticleDOI
TL;DR: In this article, the authors provide an overview of four main approaches to rational heterostructure design: coupling α-Fe2O3 with an n- or p-type semiconductor for promoting charge separation; a nanotextured conductive substrate for efficient charge collection; a surface/interface passivation layer for reduced surface and interface charge recombination; and a catalyst for accelerated water oxidation kinetics.
Abstract: Hematite (α-Fe2O3), with a bandgap suitable for absorption of the solar spectrum, is ideally suited for use as a photoanode material in photoelectrochemical (PEC) conversion of solar light into hydrogen fuel via water splitting. However, low hole mobility, short hole lifetime, high density of surface states, and slow kinetics for oxygen evolution at the α-Fe2O3/electrolyte interface have limited the PEC performance of α-Fe2O3 photoanodes to date. Along with numerous reports on doping and nanostructuring of α-Fe2O3, increased attention has been paid to α-Fe2O3 heterostructure design for improved PEC performance. This review article provides an overview of four main approaches to rational heterostructure design: coupling α-Fe2O3 with (1) an n- or p-type semiconductor for promoting charge separation; (2) a nanotextured conductive substrate for efficient charge collection; (3) a surface/interface passivation layer for reduced surface/interface charge recombination; (4) a catalyst for accelerated water oxidation kinetics. The achievements to date demonstrate that high PEC performance may be accessed with these designs. In addition, we review time-resolved laser techniques used to probe the charge carrier dynamics of these heterostructures. Dynamic studies have provided insight into the mechanisms responsible for the improved PEC performance in these materials and helped to guide continued design of α-Fe2O3 heterostructures for further enhancement of PEC water splitting. As summarized in this review article, rational heterostructure design is a promising strategy to push forward the application of α-Fe2O3 for potential low cost and high efficiency solar hydrogen conversion. A better fundamental understanding of the charge carrier dynamics in these structures in turn helps to guide and improve the heterostructure design.

413 citations

Journal ArticleDOI
TL;DR: An overview of the existing literature about lipid nanoparticles for pulmonary application is given to provide the reader with some background information for pulmonary drug delivery, i.e., anatomy and physiology of the respiratory system, formulation requirements, application forms, clearance from the lung, pharmacological benefits and nanotoxicity.

400 citations

Journal ArticleDOI
TL;DR: This review aims to understand and explain the underpinnings of the innovative concepts and strategies developed over the past decade to tune the thermodynamics and kinetics of hydrogen storage reactions, with several promising directions and strategies that could lead to the next generation of solid-state materials for hydrogen storage applications.
Abstract: Knowledge and foundational understanding of phenomena associated with the behavior of materials at the nanoscale is one of the key scientific challenges toward a sustainable energy future. Size reduction from bulk to the nanoscale leads to a variety of exciting and anomalous phenomena due to enhanced surface-to-volume ratio, reduced transport length, and tunable nanointerfaces. Nanostructured metal hydrides are an important class of materials with significant potential for energy storage applications. Hydrogen storage in nanoscale metal hydrides has been recognized as a potentially transformative technology, and the field is now growing steadily due to the ability to tune the material properties more independently and drastically compared to those of their bulk counterparts. The numerous advantages of nanostructured metal hydrides compared to bulk include improved reversibility, altered heats of hydrogen absorption/desorption, nanointerfacial reaction pathways with faster rates, and new surface states cap...

399 citations