UV-enhanced NO2 sensor using ZnO quantum dots sensitized SnO2 porous nanowires

ZnO quantum dots sensitized SnO2 porous nanowires were fabricated and designed for UV excitation gas sensor. The ZnO/SnO2 composite (SZQ1%) with the molar proportion of 1:100 exhibits excellent sensing properties to NO2 gas under UV irradiation at 40oC. The humidity stability of SZQ1% was also measured and discussed by DC reversed circuit and complex impedance curves. The gas sensing mechanism is well discussed and illustrated to the ZnO quantum dots sensitized and the increased photo-generated carriers under UV irradiation.

Люминофоры холодного голубого излучения на основе оксида алюминия, допированного диспрозием

Al2О3:Dy3+ oxides with different colors luminescence were synthesized using precursor technology. The phase composition and crystal structure of the obtained materials were established by X-ray powder diffraction analysis. The excitation and emission spectra, decay curves, thermal quenching of luminescence were studied. Under UV excitation, the phosphors exhibit blue, purplish blue, white emission depending on the concentration of dysprosium and the temperature of annealing of the Al1-xDyx(OH)(HCOO)2 precursor in air.

New Copper Bromide Organic-Inorganic Hybrid Molecular Compounds with Anionic Inorganic Core and Cationic Organic Ligands

Here, organic-inorganic hybrid molecular compounds based on copper(I) bromide have been synthesized by slow-diffusion method. The inorganic modules of these two structures are Cu2Br42− anion, and the inorganic modules are coordinated to cationic organic ligands via Cu-N coordinative bonds. Both of these compounds are luminescent, emitting green emissions under UV excitation.

Smart Mn7+ Sensing via Quenching on Dual Fluorescence of Eu3+ Complex-Modified TiO2 Nanoparticles

In this work, titania (TiO2) nanoparticles modified by Eu(TTA)3Phen complexes (ETP) were prepared by a simple solvothermal method developing a fluorescence Mn7+ pollutant sensing system. The characterization results indicate that the ETP cause structural deformation and redshifts of the UV-visible light absorptions of host TiO2 nanoparticles. The ETP also reduce the crystallinity and crystallite size of TiO2 nanoparticles. Compared with TiO2 nanoparticles modified with Eu3+ (TiO2-Eu3+), TiO2 nanoparticles modified with ETP (TiO2-ETP) exhibit significantly stronger photoluminescence under the excitation of 394 nm. Under UV excitation, TiO2-ETP nanoparticles showed blue and red emission corresponding to TiO2 and Eu3+. In addition, as the concentration of ETP in TiO2 nanoparticles increases, the PL intensity at 612 nm also increases. When ETP-modified TiO2 nanoparticles are added to an aqueous solution containing Mn7+, the fluorescence intensity of both TiO2 and ETP decreases. The evolution of the fluorescence intensity ratio (I1/I2) of TiO2 and ETP is linearly related to the concentration of Mn7+. The sensitivity of fluorescence intensity to Mn7+ concentration enables the design of dual fluorescence ratio solid particle sensors. The method proposed here is simple, accurate, efficient, and not affected by the environmental conditions.