Xiaoqian Meng,Rui Gao,Ming Zheng,Xin Zhou,Xianfa Zhang,Xiaoli Cheng,Yingming Xu,Shan Gao,Lihua Huo
Real-time monitoring of chlorine gas (Cl 2 ) with a strong irritating odor is an indispensable means of avoiding its contamination of the air and harm to the body. To achieve this purpose, a novel gas-sensitive material capable of detecting low concentrations of Cl 2 at near room temperature is developed in this paper. ZIF-8 with a kinetic diameter of 3.4 Å in the designed ZnO@ZIF-8 composites is able to sieve gas molecules with different kinetic diameters, enabling effective improvement of the selectivity of the gas-sensitive materials. In addition, the porous structure of ZIF-8 can provide more reactive sites, which is conducive to improving gas adsorption capacity and providing of channels for gas diffusion. In this study, ZnO@ZIF-8 heterojunction composites are prepared by combining the advantages of ZnO and ZIF-8, which provides a new method for real-time monitoring of low concentrations of Cl 2 , and also has potential practical applications in fields such as environmental monitoring and industrial safety.
Chlorine (Cl 2 ) is a highly hazardous and corrosive substance that can cause severe respiratory problems and skin burns in humans at low doses. The effective detection of Cl 2 has become critical for protecting both the ecological environment and public health. Herein, the oxygen vacancy-abundant SnO 2 were synthesized using SnS as template followed by the calcination method. The resultant SnO 2 -800 sensor exhibits improved sensing response to Cl 2 (about 205–10 ppm) at room temperature, together with a trace detection limit of 100 ppb. Such excellent sensing properties could be assigned to several reasons including the unique cross-linked structure, the appropriate amount of grain boundaries, and especially sufficient oxygen vacancies. The XPS, GC-MS techniques and DFT theoretical calculation were combined used to detailly investigate the sensing mechanism. This work might shed light on the rational design of high-performance sensing materials via defect engineering.
Liangwei Ma,Chengpeng Li,Qiufeng Liang,Sheng Wang,Derong Cao
We designed and synthesized three new tetraphenylethene (TPE) derivatives ( CZ-TPE , DMA-TPE and TPA-TPE ) modified with different electron rich group (carbazole, N, N -dimethylaniline and triphenylamine segments, respectively) by Knoevenagel condensation reaction. The chemical structures of these compounds are identified by NMR, MS and IR. The absorption and emission of these dyes were investigated by UV-Vis and fluorescence spectroscopy , respectively. The results shown three dyes exhibited evident aggregation-induced emission (AIE) or aggregation-induced emission enhancement (AIEE) properties with wavelength tunable emission. Their emission color can be tuned from green to orange in tetrahydrofuran/H 2 O solutions, from green to red in solid state or pure tetrahydrofuran solutions. In addition, the solution or film of TPA-TPE shown results in distinct fluorescence from “ON” to “Off” observation as well as color change from orange yellow to colorless by naked eyes when the addition of toxic Cl 2 gas, which can be used as an excellent dual chromo- and fluorogenic signal changes that is well suited for monitoring Cl 2 gas in solution, or solid film, conveniently. These results indicate TPA-TPE is a promising candidate chemosensor for the detection of Cl 2 gas.
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