scholarly journals Photocatalytic Properties of Tin Oxide and Antimony-Doped Tin Oxide Nanoparticles

2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
J. C. M. Brokken-Zijp ◽  
O. L. J. van Asselen ◽  
W. E. Kleinjan ◽  
R. van de Belt ◽  
G. de With
Keyword(s):  
Tin Oxide ◽  
Network Formation ◽  
Uv Light ◽  
Surface Group ◽  
Surface Grafting ◽  
Light Illumination ◽  
Plasmon Band ◽  
Incident Wavelength ◽  
Uv Illumination ◽  
N Doping

For the first time it is shown that N-doped SnO2nanoparticles photocatalyze directly the polymerization of the C=C bonds of (meth)acrylates under visible light illumination. These radical polymerizations also occur when these particles are doped with Sb and when the surfaces of these particles are grafted with methacrylate (MPS) groups. During irradiation with visible or UV light the position and/or intensity of the plasmon band absorption of these nanoparticles are always changed, suggesting that the polymerization starts by the transfer of an electron from the conduction band of the particle to the (meth)acrylate C=C bond. By using illumination wavelengths with a very narrow band width we determined the influence of the incident wavelength of light, the Sb- and N-doping, and the methacrylate (MPS) surface grafting on the quantum efficiencies for the initiating radical formation (Φ) and on the polymer and particle network formation. The results are explained by describing the effects of Sb-doping, N-doping, and/or methacrylate surface grafting on the band gaps, energy level distributions, and surface group reactivities of these nanoparticles. N-doped (MPS grafted) SnO2(Sb ≥ 0%) nanoparticles are new attractive photocatalysts under visible as well as UV illumination.

Cu/graphene interdigitated electrodes with various copper thicknesses for UV-illumination-enhanced gas sensors at room temperature

2020 ◽  
Vol 22 (44) ◽  
pp. 25769-25779
Author(s):  
Min Zhao ◽  
Attia Falak ◽  
Yi Tian ◽  
Lanqin Yan ◽  
Rujun Liu ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Room Temperature ◽  
High Efficiency ◽  
Uv Light ◽  
Light Illumination ◽  
Interdigitated Electrodes ◽  
Uv Illumination

High efficiency detection of NO2 and NH3 by 8 nm Cu/graphene sensor at room temperature under UV light illumination.

Photodegradation of Pb-3,4-dihydroxybenzoic acid complex under UV light illumination

2012 ◽  
Vol 65 (5) ◽  
pp. 948-953
Author(s):  
Xuefeng Hu ◽  
Wei Qin
Keyword(s):  
Uv Light ◽  
Light Illumination ◽  
Dihydroxybenzoic Acid ◽  
Solution Ph ◽  
Acid Complex ◽  
Uv Illumination ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Ph Conditions ◽  
Total Organic Carbon Analysis

The degradation of 3,4-dihydroxybenzoic acid (3,4-DHBA) in the presence and absence of Pb2+ under UV illumination was studied. Addition of Pb2+ caused the formation of precipitate during photoreaction when the solution pH was higher than 6. The presence of Pb2+ remarkably inhibited the degradation of 3,4-DHBA and its photodegradation intermediates, while complexation of 3,4-DHBA and its photodegradation intermediates with Pb2+ decreased the free Pb2+ in aqueous solutions. Molecular oxygen played an important role in photodegradation of 3,4-DHBA in the presence of Pb2+. UV–Vis spectroscopy was used to investigate the interaction between Pb2+ and 3,4-DHBA at different pH conditions, and FT-IR was used to characterize the precipitate formed during photoreaction. The mineralization of 3,4-DHBA was investigate by total organic carbon analysis.

Room-Temperature ZnO Nanoparticle Ethanol Gas Sensors under UV Illumination

2012 ◽  
Vol 486 ◽  
pp. 39-43 ◽  
Author(s):  
S.P. Chang
Keyword(s):  
Gas Sensor ◽  
Gas Sensors ◽  
Spin Coating ◽  
Room Temperature ◽  
Uv Light ◽  
Light Illumination ◽  
Zno Nanoparticle ◽  
Uv Illumination ◽  
Potential Applications ◽  
Nanoparticle Film

A zinc oxide (ZnO) nanoparticle gas sensor was formed by spin coating. We annealed the film at 400, 600, and 800°C for 1 h in air to create a gas sensor. The responses of the gas sensor to ethanol under UV light illumination were investigated. We found that the ZnO nanoparticle film annealed at 800°C had the highest sensitivity. This can be attributed to the fact that the defects of ZnO nanoparticle film annealed at 800°C are considerably more than those for the film annealed at other temperatures. This study demonstrates that ZnO nanoparticles have potential applications as room-temperature ethanol sensors.

Effect of UV Illumination on Deposition of Low-k Si-O-C(-H) Films by PECVD

2004 ◽  
Vol 449-452 ◽  
pp. 473-476 ◽  
Author(s):  
Heon Ju Lee ◽  
Chang Sil Yang ◽  
Chi Kyu Choi
Keyword(s):  
Plasma Parameter ◽  
Uv Light ◽  
Chemical Vapor ◽  
Light Illumination ◽  
Plasma Chemical ◽  
Dielectric Thin Film ◽  
Plasma Chemical Vapor Deposition ◽  
Low Dielectric ◽  
Uv Illumination ◽  
Low K

The characteristics of plasma are important for the deposition of SiOC(-H) low dielectric thin film. The effect of UV light illumination on the plasma parameter in the capacitive coupled plasma chemical vapor deposition (CCP-CVD) system is investigated. The electron density is almost not changed, but the electron temperature decreases by UV light illumination. The deposition rate increases and the dielectric constant of the film is lowered with UV light.

Properties of ZnO Nanorods Arrays Growth via Low Temperature Hydrothermal Reaction

2011 ◽  
Vol 364 ◽  
pp. 422-426 ◽  
Author(s):  
Nur Syafinaz Ridhuan ◽  
Zainovia Lockman ◽  
Azlan Abdul Aziz ◽  
Abdul Razak Khairunisak
Keyword(s):  
Low Temperature ◽  
Hydrothermal Reaction ◽  
Uv Light ◽  
Zno Nanorods ◽  
Hydrothermal Process ◽  
Oxidation Temperature ◽  
Growth Time ◽  
Ambient Light ◽  
Incident Wavelength ◽  
Uv Illumination

This work describes properties of 1-D ZnO nanorods arrays growth using low temperature hydrothermal method on a seeded substrate. The properties of ZnO seed were studied by varying thermal oxidation temperature from 250-450°C. The formation of ZnO nanorods was studied by varying the growth time during hydrothermal process. The optimum oxidation temperature to produce seeded ZnO template was 400°C. The formation of ZnO nanorods was further studied by varying hydrothermal reaction growth time from 1 to 24 hours. The optimum hydrothermal growth time of 4 hours produced blunt tip-like nanorods with length of ~735 nm and top diameter of ~66 nm. I-V characteristics of ZnO nanorods photodetector in dark, ambient light and UV light were also studied. The change in the photoconductivity under UV illumination was found to be 1 order of magnitude higher compared to dark and ambient light. With an incident wavelength of 370 nm and applied bias of 3V, the responsivity of photodetector was 5.0 mA/W, which was higher compared to other reported works. The increase of photosensitivity indicated that the produced ZnO nanorods were suitable for UV photodetector applications.

scholarly journals UV Illumination Room-Temperature ZnO Nanoparticle Ethanol Gas Sensors

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Sheng-Po Chang ◽  
Kuan-Yu Chen
Keyword(s):  
Gas Sensor ◽  
Gas Sensors ◽  
Room Temperature ◽  
Uv Light ◽  
Light Illumination ◽  
Zno Nanoparticle ◽  
Uv Illumination ◽  
Potential Applications ◽  
Film Annealing ◽  
Nanoparticle Film

Zinc oxide (ZnO) nanoparticle gas sensor was formed by spin coating. We annealed the film at 400, 600, and 800°C for 1 hour in air to make gas sensor. The responses of gas sensor to ethanol with UV light illumination were investigated. It could be observed that the ZnO nanoparticle film annealing at 800°C has the highest sensitivity. It can be attributed to the defects of ZnO nanoparticle film annealing at 800°C much more than other annealing temperatures. The study shows that the ZnO nanoparticles have potential applications as RT ethanol sensors.

scholarly journals Oxalic Acid-Induced Photodissolution of Ferrihydrite and the Fate of Loaded As(V): Kinetics and Mechanism

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1143 ◽  
Author(s):  
Hai-Tao Ren ◽  
Jing Han ◽  
Ting-Ting Li ◽  
Qi Lin ◽  
Jia-Horng Lin ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Iron Oxides ◽  
Uv Light ◽  
Water Environment ◽  
Light Irradiation ◽  
Aquatic Environments ◽  
Light Illumination ◽  
Acidic Water ◽  
Uv Illumination ◽  
Uv Light Irradiation

The fate of arsenic in the water environment is of great concern. Here, the influences of oxalic acid and UV light illumination on the dissolution of naked ferrihydrite (Fhy), Fhy loaded with As(V) [Fhy*-As(V)], as well as the fate of As(V) at pH 3.0 were studied. With the assistance of oxalic acid, complexes of Fe(III)-oxalic acid produced on Fhy/Fhy*-As(V) were reduced to Fe(II)-oxalic acid by photo-induced electrons under UV light irradiation. UV light has nearly no impact on the release of As(V) in the system of Fhy*-As(V) without the assistance of oxalic acid. Nevertheless, in the existence of oxalic acid, UV light illumination resulted in the contents of liberated As(V) decreased by 775–1300% compared to that without light. Considering the coexistence of As(V), oxalic acid as well as iron oxides in aquatic environments, the present study revealed that UV illumination could enhance the retention of As(V) on Fhy in the acidic water environment containing oxalic acid.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

scholarly journals Engineered tunneling layer with enhanced impact ionization for detection improvement in graphene/silicon heterojunction photodetectors

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Jun Yin ◽  
Lian Liu ◽  
Yashu Zang ◽  
Anni Ying ◽  
Wenjie Hui ◽  
...  
Keyword(s):  
High Performance ◽  
Impact Ionization ◽  
Low Cost ◽  
Atomic Layer ◽  
Light Illumination ◽  
Insulation Material ◽  
Defect States ◽  
Uv Illumination ◽  
Layer Deposition ◽  
The Impact

AbstractHere, an engineered tunneling layer enhanced photocurrent multiplication through the impact ionization effect was proposed and experimentally demonstrated on the graphene/silicon heterojunction photodetectors. With considering the suitable band structure of the insulation material and their special defect states, an atomic layer deposition (ALD) prepared wide-bandgap insulating (WBI) layer of AlN was introduced into the interface of graphene/silicon heterojunction. The promoted tunneling process from this designed structure demonstrated that can effectively help the impact ionization with photogain not only for the regular minority carriers from silicon, but also for the novel hot carries from graphene. As a result, significantly enhanced photocurrent as well as simultaneously decreased dark current about one order were accomplished in this graphene/insulation/silicon (GIS) heterojunction devices with the optimized AlN thickness of ~15 nm compared to the conventional graphene/silicon (GS) devices. Specifically, at the reverse bias of −10 V, a 3.96-A W−1 responsivity with the photogain of ~5.8 for the peak response under 850-nm light illumination, and a 1.03-A W−1 responsivity with ∼3.5 photogain under the 365 nm ultraviolet (UV) illumination were realized, which are even remarkably higher than those in GIS devices with either Al2O3 or the commonly employed SiO2 insulation layers. This work demonstrates a universal strategy to fabricate broadband, low-cost and high-performance photo-detecting devices towards the graphene-silicon optoelectronic integration.

Self-Assembly of Tin Oxide Nanoparticles:  Localized Percolating Network Formation in Polymer Matrix

Langmuir ◽  
2006 ◽  
Vol 22 (22) ◽  
pp. 9260-9263 ◽  
Author(s):  
Atsumi Wakabayashi ◽  
Yuki Sasakawa ◽  
Toshiaki Dobashi ◽  
Takao Yamamoto
Keyword(s):  
Polymer Matrix ◽  
Tin Oxide ◽  
Self Assembly ◽  
Network Formation ◽  
Oxide Nanoparticles ◽  
Tin Oxide Nanoparticles ◽  
Percolating Network
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