scholarly journals Fingerprinting of Nitroaromatic Explosives Realized by Aphen-functionalized Titanium Dioxide

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2407 ◽  
Author(s):  
Guanshun Xie ◽  
Bingxin Liu
Keyword(s):  
Titanium Dioxide ◽  
Homeland Security ◽  
Sensor Array ◽  
Visible Region ◽  
Excitation Wavelength ◽  
Absorption Band Edge ◽  
Nitroaromatic Explosives ◽  
Kinetics And Thermodynamics ◽  
Improvised Explosive ◽  
Improvised Explosives

Developing sensing materials for military explosives and improvised explosive precursors is of great significance to maintaining homeland security. 5-Nitro-1,10-phenanthroline (Aphen)-modified TiO2 nanospheres are prepared though coordination interactions, which broaden the absorption band edge of TiO2 and shift it to the visible region. A sensor array based on an individual TiO2/Aphen sensor is constructed by regulating the excitation wavelength (365 nm, 450 nm, 550 nm). TiO2/Aphen shows significant response to nitroaromatic explosives since the Aphen capped on the surface of TiO2 can chemically recognize and absorb nitroaromatic explosives by the formation of the corresponding Meisenheimer complex. The photocatalytic mechanism is proved to be the primary sensing mechanism after anchoring nitroaromatic explosives to TiO2. The fingerprint patterns obtained by combining kinetics and thermodynamics validated that the single TiO2/Aphen sensor can identify at least six nitroaromatic explosives and improvised explosives within 8 s and the biggest response reaches 80%. Furthermore, the TiO2/Aphen may allow the contactless detection of various explosives, which is of great significance to maintaining homeland security.

scholarly journals Comparative study of absorption band edge tailoring by cationic and anionic doping in TiO2

2018 ◽  
Vol 36 (3) ◽  
pp. 435-438
Author(s):  
Arpit Swarup Mathur ◽  
Praveen Kumar ◽  
B.P. Singh
Keyword(s):  
Titanium Dioxide ◽  
Absorption Band ◽  
Sol Gel ◽  
Visible Region ◽  
Solar Spectrum ◽  
Band Edge ◽  
Absorption Band Edge ◽  
Vis Spectroscopy ◽  
Coating Method ◽  
Nanocrystalline Titanium

AbstractTitanium dioxide (TiO2) is one of the most favored metal oxide semiconductors for the use as photoanode in photoelectrochemical cells (PEC) splitting the water into hydrogen and oxygen. However, the major impediment is its large bandgap that limits its utilization as photoanode. Doping has evolved as an effective strategy for tailoring optical and electronic properties of TiO2. This paper describes the synthesis of undoped as well as iron (Fe, cationic) and nitrogen (N, anionic) doped nanocrystalline titanium dioxide by sol-gel spin coating method for solar energy absorption in the visible region. All the prepared thin films were characterized by X-ray diffraction and UV-Vis spectroscopy. Doping of both Fe and N into TiO2 resulted in a shift of absorption band edge towards the visible region of solar spectrum.

Preparation, Characterization and its Photocatalytic Performance of Rare Earth Element Erbium Doped with TiO2 Material

2012 ◽  
Vol 568 ◽  
pp. 380-383
Author(s):  
Song Tian Li ◽  
Guo Xu He ◽  
Wei Ma ◽  
Yan Hua Liu
Keyword(s):  
Titanium Dioxide ◽  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Visible Region ◽  
Erbium Doped ◽  
Sol Gel Process ◽  
Reduce Energy Consumption

In order to expand photoresponse range of TiO2, reduce energy consumption of semiconductor material optical catalytic, certain amount of rare earth element Erbiun was doped during preparation of anatase titanium dioxide to improve the light absorption and photocatalysis efficiency. A series of rare earth element doped TiO2 material were prepared by sol-gel process, and characterized by means of UV-vis diffuse reflectance spectra. UV-vis absorption verified that doping of Er3+ enhanced absorptive capacity of catalyst in visible region. The photocatalytic performance of anatase titanium dioxide and rare earth element Erbiun doped with TiO2 to basic fuchsin were studied.

Determination and identification of nitroaromatic explosives by a double-emitter sensor array

Talanta ◽  
2019 ◽  
Vol 201 ◽  
pp. 230-236 ◽  
Author(s):  
Forough Ghasemi ◽  
M. Reza Hormozi-Nezhad
Keyword(s):  
Sensor Array ◽  
Nitroaromatic Explosives

scholarly journals Simultaneous colorimetric detection of improvised explosive compounds using microfluidic paper-based analytical devices (μPADs)

2015 ◽  
Vol 7 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Kelley L. Peters ◽  
Inge Corbin ◽  
Lindsay M. Kaufman ◽  
Kyle Zreibe ◽  
Lucas Blanes ◽  
...  
Keyword(s):  
Colorimetric Detection ◽  
Improvised Explosive ◽  
Improvised Explosives

In this paper the development of microfluidic paper-based analytical devices (μPADs) is described for the rapid, on-site detection of improvised explosives.

COMPOSITES OF THE TITANIA THIN FILMS IMPLANTED BY Ge AND Si

2011 ◽  
Vol 25 (12) ◽  
pp. 1629-1635 ◽  
Author(s):  
YANJUN ZHOU ◽  
FANG HE ◽  
YUAN HUANG ◽  
YIZAO WAN ◽  
YULIN WANG
Keyword(s):  
Thin Films ◽  
Titanium Dioxide ◽  
Photoelectron Spectroscopy ◽  
Quartz Substrate ◽  
Visible Region ◽  
Silicon Oxides ◽  
Practical Applications ◽  
Chemical States ◽  
Titanium Dioxide Thin Films ◽  
Implantation Method

By using reactive magnetron sputtering system, titanium dioxide thin films were fabricated onto quartz substrate, and then modified by Ge and Si atoms that were introduced with ion implantation method. XRD, AFM, XPS, and UV-vis were used to characterize these films, and X-ray photoelectron spectroscopy (XPS) was adopted to examine the atomic chemical states of implanted titanium dioxide thin films. The results show that there are Ge and silicon oxides precipitations in TiO 2 matrices. The implanted Ge + Si thin film exhibits an intense absorption band within visible region, which will further benefit its practical applications.

Effect of Sputtering Pressure on Optimization of Titanium Dioxide Nanostructures Prepared by RF Magnetron Sputtering

2013 ◽  
Vol 667 ◽  
pp. 452-457 ◽  
Author(s):  
N.A.M. Asib ◽  
Mohamed Zahidi Musa ◽  
Saifollah Abdullah ◽  
Mohamad Rusop
Keyword(s):  
Surface Roughness ◽  
Titanium Dioxide ◽  
Magnetron Sputtering ◽  
Visible Region ◽  
Rf Magnetron Sputtering ◽  
Transmission Spectra ◽  
Cross Sectional ◽  
Vis Spectroscopy ◽  
Sputtering Pressure ◽  
Tio2 Nanostructures

Titanium dioxide (TiO2) nanostructures were deposited on glass substrate by Radio Frequency (RF) magnetron sputtering. The samples deposited at various sputtering pressures and annealed at 723 K, were characterized using Atomic Force Microscope (AFM) to observe the surface morphology and topology, roughness properties and cross-sectional of TiO2 nanostructures, Field Emission Scanning Electrons Microscope (FESEM) to observe the particle sizes of TiO2 nanostructures and UV-vis spectroscopy to record the UV-vis transmission spectra. The aim of this paper is to determine which parameter of sputtering pressures influence the optimization of TiO2 nanostructures. AFM images show that the surface roughness of the samples decreases as the working pressures of sputtering increases. From FESEM images, it can be deduced that the higher the sputtering pressure, the smaller the particle size is. All the samples are highly transmittance with an average transmittance higher than 80% in the visible region as recorded by UV-vis transmission spectra. The relatively high transmittance of the sample indicates its low surface roughness and good homogeneity. For optimum TiO2 nanostructures deposited at various RF pressures it has the lowest surface roughness and the smallest TiO2 size particles with the indirect optical band gap of 3.41 eV.

Synthesis of PBMA-b-PGMA Block Copolymers via ICAR ATRP and their Application in Polymer/Titanium Dioxide Hybrid Materials

2016 ◽  
Vol 41 ◽  
pp. 63-73 ◽  
Author(s):  
Jiang Ping Sun ◽  
Yang Zhang ◽  
Jian Li ◽  
Chen Yi Wang ◽  
Qiang Ren
Keyword(s):  
Titanium Dioxide ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Organic Solvent ◽  
Ethyl Acetate ◽  
Visible Region ◽  
Amine Group ◽  
Copper Bromide ◽  
Grafted Nanoparticles ◽  
Good Transparency

Well-defined functional block copolymers, polybutyl methacrylate-b-polyglycidyl methacrylate (PBMA-b-PGMA), were successfully synthesized via initiators for continuous activator regeneration atom transfer radical polymerization ( ICAR ATRP) with pentamethyldiethylene-triamine (PMDETA) as a ligand and copper bromide (CuBr2 ) as a catalyst with concentration of 500 ppm. The PBMA-b-PGMA grafted with titanium dioxide (TiO2 ) nanoparticles was obtained through the reaction between the epoxide on the PGMA segment and amine group on the surface of modified TiO2 nanoparticles. Results showed that the PBMA-b-PGMA block copolymer with about same length of PBMA and PGMA segment could get highest graft ratio and about 17%wt TiO2 nanoparticles were successfully grafted onto the PBMA-b-PGMA block copolymer. The sizes of the PBMA-b-PGMA grafted nanoparticles were about 74 nm in ethyl acetate. The PBMA-b-PGMA grafted TiO2 nanoparticles showed very good dispensability in organic solvent (e.g. ethyl acetate) and polymer matrix. Polymethyl methacrylate (PMMA) containing 0.5%wt PBMA-b-PGMA grafted TiO2 nanoparticles showed strong absorption at about 300 nm and good transparency in visible region, which was attributed to good dispensability of PBMA-b-PGMA grafted TiO2 nanoparticles in PMMA matrix.

scholarly journals Detection and Imaging of Underground Objects for Distinguishing Explosives by Using a Fluxgate Sensor Array

2019 ◽  
Vol 9 (24) ◽  
pp. 5415 ◽  
Author(s):  
Serkan Gürkan ◽  
Mustafa Karapınar ◽  
Seydi Doğan
Keyword(s):  
Sensor Array ◽  
Experimental Studies ◽  
Field Measurements ◽  
Success Rates ◽  
Fluxgate Sensor ◽  
Sensor Position ◽  
Explosive Properties ◽  
Improvised Explosive ◽  
Explosive Devices ◽  
Data Matrices

Active and passive techniques are two different techniques with which to detect buried explosives. In practice, the most preferred active method works by broadcasting a signal underground. This signal may stimulate the buried explosive and cause it to explode. It is important to eliminate or minimize this drawback to ensure the safety of the detector operator. In this respect, it is important to increase the studies on the passive detection technique which is not currently used in practice. The aim of this study was to passively detect improvised explosive devices without stimulating them, and to classify underground objects as explosive or non-explosive. A fluxgate sensor array having 33 components was used for passive magnetic field measurements, and the nearest neighborhood algorithm was preferred for classifying the resulting data. In experimental studies, 33 different samples having different amounts of ferromagnetic properties were used. Successful imaging and classification were achieved for the measurements up to 20 cm below the surface of soil. Data were recorded as 32 × 25 matrices, and then they were reduced to 32 × 2 matrices having the same features. Samples having explosive properties were distinguished from other underground objects with success rates of 86% and 95% for 32 × 25 and 32 × 2 data matrices, respectively. Classification times for 32 × 25 and 32 × 2 data matrices were 42 ms and 3.62 ms, respectively. For data groups where the best results were obtained for the data matrices, frame numbers classified in one second were calculated as 23.80 and 276.2, respectively. False alarm rate achieved was 5.31%. The experimental results proved the successes of the matrices reduction and classification approach. One of the most common problems encountered in passive detecting techniques is that the sensor position affects the measurements negatively. In this paper, a solution has been proposed for this important problem.

Sonocatalytic degradation of Acid Red 1 by sonochemically synthesized zinc sulfide-titanium dioxide nanotubes: Optimization, kinetics and thermodynamics studies

2019 ◽  
Vol 215 ◽  
pp. 1341-1350 ◽  
Author(s):  
Ali Mehrizad ◽  
Mohammad A. Behnajady ◽  
Parvin Gharbani ◽  
Shervin Sabbagh
Keyword(s):  
Titanium Dioxide ◽  
Zinc Sulfide ◽  
Titanium Dioxide Nanotubes ◽  
Kinetics And Thermodynamics ◽  
Acid Red 1
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