JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Jia Yang,Lifang Yuan,Di Qian,Haoyi Wu,Yahong Jin
Broadband near-infrared phosphor-converted LED (NIR pc-LED) light sources have attracted considerable attentions due to their widespread applications in active security defense, nondestructive detection, and online chemometric analysis. The broadband NIR phosphor, determining the overall performance of NIR pc-LED, is still to be explored. In this study, a series of CdGa 2-x O 4 :xCr 3+ phosphors are prepared by a solid state reaction. Owning to the electron population in 2 E and 4 T 2 energy levels of Cr 3+ ions with an intermediate crystal field, CdGa 2 O 4 :Cr 3+ exhibits a sharp line and broad band overlapped NIR emission spectrum, covering 600–1300 nm with a peak wavelength ( λ max ) of 740 nm and a full width at half maximum (FWHM) of 160 nm. A robust luminescence thermal stability that the NIR emission intensity remains 95 % of the initial level at 423 K is achieved, caused by a weak electron-phonon coupling (EPC) effect. Finally, a prototype NIR pc-LED is fabricated by using the as-obtained broadband NIR phosphor to demonstrate the application for night vision.
研究领域:
材料科学
·
光电技术
·
光子学
✓ 已验证
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2018
·
IF 9.89
Hui Chen,Lei Sun,Guo-Dong Li,Xiaoxin Zou
Surface oxygen chemistry of semiconductor metal oxides is the basis for the sensing reaction between the preadsorbed surface oxygen and the target gases or organic vapors that are to be detected, and thus fundamentally determines their sensing performances. Herein, we, for the first time, identify a novel semiconductor spinel oxide, CdGa2O4, that has suitable surface oxygen chemistry and exhibits excellent selectivity and response toward formaldehyde. Moreover, we find that a cation off-stoichiometric CdGa2O4 spinel oxide decorated with a small amount of CdO nanocrystals can further improve the formaldehyde response, without losing the selectivity. This is based on the advantages of an increased amount of adsorbed oxygen in the Ga-rich environment, as well as heterojunctions between CdO nanoparticles and Ga-rich spinel oxide. Sensing performance (e.g., selectivity and response) of the material is much better than that of most reported nanostructured metal oxides used for formaldehyde detection. Our findings propose a general approach for achieving highly selective and sensitive detection of target gases by optimizing the surface oxygen property of semiconductor oxides.
研究领域:
材料科学
·
传感器技术
·
化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Huixuan Chen,Jiayu Li,Siwen Tao,Xinhua Tian,Xikun Sun,Ruiqin Gao,Ni Bai,Guo-Dong Li
Developing fast, accurate and sensitive triethylamine gas sensors with low detection limits is paramount to ensure the safety of workers and the public. However, sensors based on single metal oxide materials still suffer from drawbacks such as low response sensitivity and long response and recovery times. To address these challenges, in this work, a series of mesoporous CdO/CdGa 2 O 4 microspheres were synthesized. We optimized the sensor's sensing performance to triethylamine by fine-tuning the ratio of CdO to CdGa 2 O 4 . Among them, CdO:3CdGa 2 O 4 -based sensor demonstrates a rapid response time of 2 s to detect 100 ppm of triethylamine, with a high response value of 211 and exceptional selectivity. Furthermore, it exhibits a low detection limit of 20 ppb for triethylamine, making it suitable for practically testing fish freshness. Crucially, electron transfer between the heterojunctions increases the chemically adsorbed oxygen on the materials’ surface, thereby enhancing the sensor's response sensitivity to triethylamine. This discovery provides new insights and methodologies for the design of highly efficient triethylamine gas sensors.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Qihua Liang,Jingjing Zheng,Xiaotian Li,Bo Zhang,Ni Bai,Guo-Dong Li
Spinel metal oxides , prepared at high temperature, have shown excellent gas sensing properties among metal oxide sensing materials. Herein, a series of porous spinel gallate nanospheres, including CdGa 2 O 4 , NiGa 2 O 4 , CoGa 2 O 4 , CuGa 2 O 4 , ZnGa 2 O 4 , and MgGa 2 O 4 were prepared by solvothermal method and followed low temperature calcination . XRD , SEM, XPS and N 2 adsorption-desorption have been carried out to determine their structure, morphology, chemical state and surface area, respectively. These nanospheres are all composed of tiny nanoparticles , giving meso-porous characters. Furthermore, the sensor based on CdGa 2 O 4 exhibits excellent formaldehyde sensing performance, including good selectivity, short response time, and excellent stability at the low working temperature of 120 °C.
研究领域:
材料科学
·
纳米技术
·
环境监测
·
化学传感
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）