Three-dimensional （3D） hierarchical Co3O4 microcrystal with radial dendritic morphologies was prepared through hydrothermal reactions followed by subsequent annealing treatment. Structural and morphological characte...Three-dimensional （3D） hierarchical Co3O4 microcrystal with radial dendritic morphologies was prepared through hydrothermal reactions followed by subsequent annealing treatment. Structural and morphological characterizations were performed by X-ray diffraction, scan-ning electron microscopy and transmission electron microscopy. The gas sensing properties of the as-obtained microcrystal were investigated at 110 oC, which revealed that the 3D hierarchical porous Co3O4 microcrystal exhibited high sensitivity to ammonia, as well as a short response time of 10 s. The response characteristic indicates that the sensor has a good stability and reversibility. Detections of toxic and flammable gases, such as ethanol, acetone and benzene were also carried out at a relative low temperature. The results indicate that such hierarchical Co3O4 microcrystal would be a potential material in the field of gas sensing.展开更多
A high-sensitivity sensor for multiple gases based on microring array filter and fiber loop ring-down spectroscopy system is proposed and demonstrated. The parameters of the resonators are designed so that the filtere...A high-sensitivity sensor for multiple gases based on microring array filter and fiber loop ring-down spectroscopy system is proposed and demonstrated. The parameters of the resonators are designed so that the filtered signal from a broadband light source can be tuned with an absorption spectral line of gas. Therefore, through adding microring resonators horizontally and vertically, the number of target gases and filter range are increased. In this research, in the broad spectral range of about 0.9 μm, only the absorption spectral lines of target gases are filtered. The simulation results show that three target gases, CH_4, CO_2 and HF, can be simultaneously detected by the sensing system. Owing to the fiber loop ring-down spectroscopy, the whole system is optimized in mini-size and sensitivity, and we can choose different sensing methods to enhance the measurement accuracy for high and low concentration conditions.展开更多
基金ACKNOWLEDGMENTS This work was supported by the 211 project of Anhui University, the National Natural Science Foundation of China （No.11374013, No.61290301, No.51072001, No.51272001, and No.51272003）, Anhui Provincial Natural Science Fund （No.l1040606M49）, Higher Educational Natural Science Foundation of Anhui Province （No.KJ2012A007）, and the PhD Start-up Fund of Anhui University （No.33190209）. Ming-zai Wu thanks Dr. Fan-li Meng and Miss Hui-hua Li from the Institute of Intelligent Machines, CAS for the help with gas sensing experiment.
文摘Three-dimensional （3D） hierarchical Co3O4 microcrystal with radial dendritic morphologies was prepared through hydrothermal reactions followed by subsequent annealing treatment. Structural and morphological characterizations were performed by X-ray diffraction, scan-ning electron microscopy and transmission electron microscopy. The gas sensing properties of the as-obtained microcrystal were investigated at 110 oC, which revealed that the 3D hierarchical porous Co3O4 microcrystal exhibited high sensitivity to ammonia, as well as a short response time of 10 s. The response characteristic indicates that the sensor has a good stability and reversibility. Detections of toxic and flammable gases, such as ethanol, acetone and benzene were also carried out at a relative low temperature. The results indicate that such hierarchical Co3O4 microcrystal would be a potential material in the field of gas sensing.
基金supported by the National Natural Science Foundation of China(Nos.61471210 and 61501271)Happiness Foundation of Wang Kuancheng
文摘A high-sensitivity sensor for multiple gases based on microring array filter and fiber loop ring-down spectroscopy system is proposed and demonstrated. The parameters of the resonators are designed so that the filtered signal from a broadband light source can be tuned with an absorption spectral line of gas. Therefore, through adding microring resonators horizontally and vertically, the number of target gases and filter range are increased. In this research, in the broad spectral range of about 0.9 μm, only the absorption spectral lines of target gases are filtered. The simulation results show that three target gases, CH_4, CO_2 and HF, can be simultaneously detected by the sensing system. Owing to the fiber loop ring-down spectroscopy, the whole system is optimized in mini-size and sensitivity, and we can choose different sensing methods to enhance the measurement accuracy for high and low concentration conditions.
