scholarly journals Zn Doped α-Fe2O3: An Efficient Material for UV Driven Photocatalysis and Electrical Conductivity

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 273 ◽  
Author(s):  
Suman ◽  
Surjeet Chahal ◽  
Ashok Kumar ◽  
Parmod Kumar
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Uv Light ◽  
Sol Gel ◽  
High Energy ◽  
Lattice Parameter ◽  
Dielectric Behavior ◽  
Energy Storage Devices ◽  
Vis Spectroscopy ◽  
Potential Applications

Zinc (Zn) doped hematite (α-Fe2O3) nanoparticles with varying concentrations (pure, 2%, 4% and 6%) were synthesized via sol-gel method. The influence of divalent Zn ions on structural, optical and dielectric behavior of hematite were studied. X-ray diffraction (XRD) pattern of synthesized samples were indexed to rhombohedral R3c space group of hematite with 14–21 nm crystallite size. The lattice parameter (a and c) values increase upto Zn 4% and decrease afterwards. The surface morphology of prepared nanoparticles were explored using transmission electron microscopy (TEM). The band gap measured from Tauc’s plot, using UV-Vis spectroscopy, showed reduction in its values upto Zn 4% and the reverse trend was obtained in higher concentrations. The dielectric properties of pure and Zn doped hematite were investigated at room temperature and followed the same trends as that of XRD parameters and band gap. Photocatalytic properties of nanoparticles were performed for hazardous Rose bengal dye and showed effective degradation in the presence of UV light. Hence, Zn2+ doped hematite can be considered as an efficient material for the potential applications in the domain of photocatalysis and also higher value of dielectric constant at room temperature makes them applicable in high energy storage devices.

scholarly journals Monocarborane cluster as a stable fluorine-free calcium battery electrolyte

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kazuaki Kisu ◽  
Sangryun Kim ◽  
Takara Shinohara ◽  
Kun Zhao ◽  
Andreas Züttel ◽  
...  
Keyword(s):  
Room Temperature ◽  
Coulombic Efficiency ◽  
Low Cost ◽  
Ionic Conductivities ◽  
High Energy ◽  
High Energy Density ◽  
Free Calcium ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Battery Electrolyte

AbstractHigh-energy-density and low-cost calcium (Ca) batteries have been proposed as ‘beyond-Li-ion’ electrochemical energy storage devices. However, they have seen limited progress due to challenges associated with developing electrolytes showing reductive/oxidative stabilities and high ionic conductivities. This paper describes a calcium monocarborane cluster salt in a mixed solvent as a Ca-battery electrolyte with high anodic stability (up to 4 V vs. Ca2+/Ca), high ionic conductivity (4 mS cm−1), and high Coulombic efficiency for Ca plating/stripping at room temperature. The developed electrolyte is a promising candidate for use in room-temperature rechargeable Ca batteries.

scholarly journals Visible-Light Photoswitching of G-Quadruplex Ligand Binding Mode Allows Reversible Control of G-Tetrad Structure

2020 ◽  
Author(s):  
Michael O'Hagan ◽  
Javier Ramos Soriano ◽  
Susanta Haldar ◽  
Juan Carlos Morales ◽  
Adrian Mulholland ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Visible Light ◽  
Uv Light ◽  
Binding Mode ◽  
High Energy ◽  
Light Sources ◽  
Biologically Relevant ◽  
G Quadruplex ◽  
Potential Applications ◽  
Robust Regulation

<div><p>Photoresponsive ligands for G-quadruplex oligonucleotides (G4) offer exciting opportunities for the reversible regulation of these assemblies with potential applications in biological chemistry and responsive nanotechnology. However, achieving the robust regulation of G4 ligand activity with low-energy visible light sources that are easily accessible and compatible with biological systems remains a significant challenge to realizing these applications. Herein, we report the G4-binding properties of a photoresponsive dithienylethene (DTE). We demonstrate the first example of G4-specific acceleration of the photoswitching kinetics of a small molecule and the visible-light mediated switching of the G4 ligand binding mode in physiologically-relevant conditions, which in turn allows control over the G4 tetrad structure of telomeric G4 in potassium buffer. The process is fully reversible and avoids the need for high-energy UV light. This affords an efficient, practical and biologically-relevant means of control that may be applied in the generation of new responsive G4/ligand supramolecular systems.</p></div><br>

Synthesis of NiCo2S4@NiMoO4 Nanosheets with Excellent Electrochemical Performance for Supercapacitor

2021 ◽  
Author(s):  
Yucai Li ◽  
Yan Zhao ◽  
Shiwei Song ◽  
Jian wang
Keyword(s):  
Electrode Materials ◽  
High Specific Capacitance ◽  
High Energy ◽  
High Energy Density ◽  
Cycle Performance ◽  
Ni Foam ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Excellent Electrochemical Performance ◽  
Potential Applications

Abstract Core-shell structured NiCo2S4@NiMoO4 is considered to be one of the most promising electrode materials for supercapacitors due to its high specific capacitance and excellent cycle performance. In this work, we report NiCo2S4@NiMoO4 nanosheets on Ni foam by two-step fabricated method. The as-obtained product has high capacitance of 1102.5 F g− 1 at 1 A g− 1. The as-assembled supercapacitor has also a high energy density of 37.6 W h kg− 1 and superior cycle performance with 85% capacitance retention. The electrode materials reported here might exhibits potential applications in future energy storage devices.

scholarly journals Enhanced Humidity Sensing Response of SnO2/Silicon Nanopillar Array by UV Irradiation

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2141 ◽  
Author(s):  
Wei Li ◽  
Linlin Wang ◽  
Yun Cai ◽  
Peifeng Pan ◽  
Jinze Li ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Response Time ◽  
Specific Surface ◽  
Uv Irradiation ◽  
Recovery Time ◽  
Room Temperature ◽  
Uv Light ◽  
Humidity Sensing ◽  
Potential Applications ◽  
Humidity Sensitivity

In this work, a silicon nanopillar array was created with nanosphere lithography. SnO2 film was deposited on this nanostructure by magnetron sputtering to form an SnO2/silicon nanopillar array sensor. The humidity sensitivity, response time, and recovery time were all measured at room temperature (25 °C) with UV or without UV irradiation. As a result, the humidity sensitivity properties were improved by enlarging the specific surface area with ordered nanopillars and irradiating with UV light. These results indicate that nanostructure sensors have potential applications in the field of sensors.

scholarly journals Room Temperature Synthesis of V-Doped TiO2 and Its Photocatalytic Activity in the Removal of Caffeine under UV Irradiation

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 911 ◽  
Author(s):  
Olga Sacco ◽  
Diana Sannino ◽  
Mariantonietta Matarangolo ◽  
Vincenzo Vaiano
Keyword(s):  
Room Temperature ◽  
Uv Light ◽  
Sol Gel ◽  
Doped Tio2 ◽  
Toc Removal ◽  
Calcination Step ◽  
Caffeine Degradation ◽  
Wavelength Emission ◽  
Sol Gel Synthesis ◽  
Uv Leds

In this work, the influence of simple acids in the room temperature sol-gel synthesis of TiO2 was investigated and the efficiency of prepared photocatalysts was evaluated in the removal of caffeine. To improve the photoactivity of TiO2, vanadium-doped TiO2 (VTiO2) samples were obtained starting from different amount of vanadyl sulphate as a dopant source. The samples were centrifuged, washed and finally dried at room temperature, and no calcination step was carried out. The prepared photocatalysts were characterized by different techniques (X-ray powder diffraction (XRD), specific surface area (SSA), ultraviolet-visible diffuse reflectance spectra (UV-vis DRS) and Raman). VTiO2 photocatalysts were tested in the photocatalytic removal of aqueous solutions containing caffeine. The photocatalytic tests were carried out in a recirculating batch cylindrical photoreactor irradiated by a UV LEDs strip (nominal power of 12 W and wavelength emission peak at about 365 nm) surrounding the external surface of the reactor. The optimized VTiO2 photocatalyst was able to reach a caffeine degradation of about 96% after 360 min of UV light irradiation with a total organic carbon (TOC) removal of 72%.

LIGHT-INDUCED AGGREGATION OF NANOPARTICLES FUNCTIONALIZED WITH 7-AMINO-4-METHYLCOUMARIN

Nano LIFE ◽  
2012 ◽  
Vol 02 (03) ◽  
pp. 1241007 ◽  
Author(s):  
JOSHUA E. ROSEN ◽  
LYNDON JONES ◽  
FRANK X. GU
Keyword(s):  
Reductive Amination ◽  
Uv Light ◽  
Synthesis Method ◽  
The Body ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Different Types ◽  
Potential Applications ◽  
Nanoparticle Formulation ◽  
Induced Aggregation

Herein, we report on the modification of silica nanoparticles with the molecule 7-amino-4-methylcoumarin (AMC) via a hydrophilic dextran linker using reductive amination chemistry. The AMC-functionalized nanoparticles were shown to aggregate in response to irradiation by 350 nm UV light. The aggregation of the particles was studied using dynamic light scattering, UV-VIS spectroscopy, and transmission electron microscopy. The synthesis method described herein utilizes a classic reductive amination reaction, which can potentially be transferred to a variety of different types of nanoparticles. Particles displaying this behavior have many potential applications in the field of nanomedicine, as they can potentially allow one to modulate the particle size of a nanoparticle formulation after administration to the body. The AMC-functionalized particles studied in this report serve as a convincing proof-of-concept for synthesizing light-responsive nanoparticles.

Spherical SiO2 @ GdPO4 : Eu3+ Core–Shell Phosphors: Sol–Gel Synthesis and Characterization

2007 ◽  
Vol 7 (2) ◽  
pp. 542-548 ◽  
Author(s):  
Cuikun Lin ◽  
Bo Zhao ◽  
Zhenling Wang ◽  
Min Yu ◽  
Huan Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Low Voltage ◽  
Uv Light ◽  
Sol Gel ◽  
Emission Spectra ◽  
Core Shell ◽  
Time Resolved ◽  
Potential Applications ◽  
Ft Ir ◽  
Red Luminescence

Nanocrystalline GdPO4 : Eu3+ phosphor layers were coated on non-aggregated, monodisperse and spherical SiO2 particles by Pechini sol–gel method, resulting in the formation of core–shell structured SiO2 @ GdPO4 : Eu3+ particles. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), photoluminescence (PL), low-voltage cathodoluminescence (CL), time-resolved PL spectra and lifetimes were used to characterize the core–shell structured materials. Both XRD and FT-IR results indicate that GdPO4 layers have been successfully coated on the SiO2 particles, which can be further verified by the images of FESEM and TEM. Under UV light excitation, the SiO2 @ GdPO4 : Eu3+ phosphors show orange-red luminescence with Eu3+ 5D0–7F1 (593 nm) as the most prominent group. The PL excitation and emission spectra suggest that an energy transfer occurs from Gd3+ to Eu3+ in SiO2 @ GdPO4 : Eu3+ phosphors. The obtained core–shell phosphors have potential applications in FED and PDP devices.

Band-Gap Engineering Based on Ti@ZnO Nanocolloids: Tunable Optical Properties

2014 ◽  
Vol 617 ◽  
pp. 161-165
Author(s):  
Chrystelle Neaime ◽  
Fabien Grasset ◽  
Tangi Aubert
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Uv Light ◽  
Sol Gel ◽  
Wide Band ◽  
Colloidal Solutions ◽  
Light Emitters ◽  
Wide Range ◽  
High Concentrations ◽  
Acoustic Wave Devices

One of the largest application areas of sol-gel chemistry is thin-film preparation. Using this approach, we started to synthesize M@ZnO colloidal solutions for the preparation of functional thin films. ZnO is a wide band-gap (3.37 eV) semiconductor with large exciton binding energy. In the bulk or in nanosized form, it could be used in a wide range of applications such as UV light emitters, spin functional devices, gas sensors, transparent electronics or surface acoustic wave devices. Since recently, the preparation of innovative functional M@ZnO materials by doping or functionalizing nanocolloids constitutes a new challenge. Using high concentrations of the different Ti@ZnO nanocolloids, we were able to prepare various functional colloidal solutions with tunable emission and thin films, such as red-luminescent Eu3+@ZnTiO3 or versatile ZnTiON colored nanomaterials.

Preparation and Characterization of Pd-Based Optical Hydrogen Sensor Operated at Room Temperature by Using Photodeposition Process

2010 ◽  
Vol 445 ◽  
pp. 100-104 ◽  
Author(s):  
Junichi Hamagami ◽  
Ryo Araki ◽  
Hiroyuki Oda ◽  
Mototsugu Sakai ◽  
Atsunori Matsuda
Keyword(s):  
Thin Film ◽  
Glass Substrate ◽  
Room Temperature ◽  
Tio2 Thin Film ◽  
Uv Light ◽  
Sol Gel ◽  
Optical Transmittance ◽  
Pd Nanoparticles ◽  
Hydrogen Gas ◽  
Hot Water

Palladium (Pd) nanoparticles were prepared on photocatalytic TiO2-coated glass substrate by a photodeposition process and the optical hydrogen sensing properties were examined at room temperature. The TiO2 coatings were prepared on a non-alkaline glass substrate by a sol-gel process and hot water treatment. Pd nanoparticles were deposited on the TiO2 film by photodeposition using UV light. The obtained Pd/TiO2 thin film showed remarkable optical transmittance response to hydrogen gas at room temperature. The normalized transmittance of the Pd/TiO2 thin film at a wavelength of 640 nm decreased to 0.9 on exposing the film to hydrogen gas for only 5 s. This transmittance decrease is considered to be due to a gaschromic effect of the TiO2 photocatalytic coating.

Self-Cleaning TiO2/SiO2 Thin Film Prepared by a Simple Sol-Gel Method

2014 ◽  
Vol 804 ◽  
pp. 157-160
Author(s):  
Wen Xiu Liu ◽  
Jun Na Xu ◽  
Jun Zhang ◽  
Xue Mei Liu ◽  
Wen Bin Cao
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Sulfate Solution ◽  
Ultraviolet Region ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Titanyl Sulfate ◽  
Glass Substrates ◽  
Light Region ◽  
Vis Spectroscopy

TiO2 thin films were prepared on SiO2-coated glass substrates using sols deriving from high concentration titanyl sulfate solution by the spin-coating technique. The calcined films were characterized by X-ray diffraction, UV-Vis spectroscopy, scanning electron microscopy. The film exhibited high transmittance in the visible light region and high absorption in the ultraviolet region. The contact angle of SiO2/TiO2 decreased to below 5° under 30 min of UV light irradiation and can sustain for 1 weeks.

Sign in / Sign up

Export Citation Format

Share Document