3D micro-combs self-assembled from 2D N-doped In2S3 for room-temperature reversible NO2 gas sensing

2022 ◽  
Vol 26 ◽  
pp. 101355
Author(s):  
Yinfen Cheng ◽  
Zhong Li ◽  
Tao Tang ◽  
Kai Xu ◽  
Hao Yu ◽  
...  
Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 317 ◽  
Author(s):  
Haihong Yin ◽  
Changqing Song ◽  
Zhiliang Wang ◽  
Haibao Shao ◽  
Yi Li ◽  
...  

VO2(B), VO2(M), and V2O5 are the most famous compounds in the vanadium oxide family. Here, their gas-sensing properties were investigated and compared. VO2(B) nanoflakes were first self-assembled via a hydrothermal method, and then VO2(M) and V2O5 nanoflakes were obtained after a heat-phase transformation in nitrogen and air, respectively. Their microstructures were evaluated using X-ray diffraction and scanning and transmission electron microscopies, respectively. Gas sensing measurements indicated that VO2(M) nanoflakes were gas-insensitive, while both VO2(B) and V2O5 nanoflakes were highly selective to ammonia at room temperature. As ammonia sensors, both VO2(B) and V2O5 nanoflakes showed abnormal p-type sensing characteristics, although vanadium oxides are generally considered as n-type semiconductors. Moreover, V2O5 nanoflakes exhibited superior ammonia sensing performance compared to VO2(B) nanoflakes, with one order of magnitude higher sensitivity, a shorter response time of 14–22 s, and a shorter recovery time of 14–20 s. These characteristics showed the excellent potential of V2O5 nanostructures as ammonia sensors.


Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 303
Author(s):  
Hui Zhou ◽  
Kai Xu ◽  
Nam Ha ◽  
Yinfen Cheng ◽  
Rui Ou ◽  
...  

Reversible H2 gas sensing at room temperature has been highly desirable given the booming of the Internet of Things (IoT), zero-emission vehicles, and fuel cell technologies. Conventional metal oxide-based semiconducting gas sensors have been considered as suitable candidates given their low-cost, high sensitivity, and long stability. However, the dominant sensing mechanism is based on the chemisorption of gas molecules which requires elevated temperatures to activate the catalytic reaction of target gas molecules with chemisorbed O, leaving the drawbacks of high-power consumption and poor selectivity. In this work, we introduce an alternative candidate of cobalt oxysulfide derived from the calcination of self-assembled cobalt sulfide micro-cages. It is found that the majority of S atoms are replaced by O in cobalt oxysulfide, transforming the crystal structure to tetragonal coordination and slightly expanding the optical bandgap energy. The H2 gas sensing performances of cobalt oxysulfide are fully reversible at room temperature, demonstrating peculiar p-type gas responses with a magnitude of 15% for 1% H2 and a high degree of selectivity over CH4, NO2, and CO2. Such excellent performances are possibly ascribed to the physisorption dominating the gas–matter interaction. This work demonstrates the great potentials of transition metal oxysulfide compounds for room-temperature fully reversible gas sensing.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1360
Author(s):  
Qiaohua Feng ◽  
Huanhuan Zhang ◽  
Yunbo Shi ◽  
Xiaoyu Yu ◽  
Guangdong Lan

A sensor operating at room temperature has low power consumption and is beneficial for the detection of environmental pollutants such as ammonia and benzene vapor. In this study, polyaniline (PANI) is made from aniline under acidic conditions by chemical oxidative polymerization and doped with tin dioxide (SnO2) at a specific percentage. The PANI/SnO2 hybrid material obtained is then ground at room temperature. The results of scanning electron microscopy show that the prepared powder comprises nanoscale particles and has good dispersibility, which is conducive to gas adsorption. The thermal decomposition temperature of the powder and its stability are measured using a differential thermo gravimetric analyzer. At 20 °C, the ammonia gas and benzene vapor gas sensing of the PANI/SnO2 hybrid material was tested at concentrations of between 1 and 7 ppm of ammonia and between 0.4 and 90 ppm of benzene vapor. The tests show that the response sensitivities to ammonia and benzene vapor are essentially linear. The sensing mechanisms of the PANI/SnO2 hybrid material to ammonia and benzene vapors were analyzed. The results demonstrate that doped SnO2 significantly affects the sensitivity, response time, and recovery time of the PANI material.


2021 ◽  
Vol 332 ◽  
pp. 129493
Author(s):  
Jae-Hun Kim ◽  
Jin-Young Kim ◽  
Ali Mirzaei ◽  
Hyoun Woo Kim ◽  
Sang Sub Kim

Author(s):  
Tianding CHEN ◽  
Wenhao YAN ◽  
Ying WANG ◽  
Jinli Li ◽  
Haibo Hu ◽  
...  

Nitrogen dioxide (NO2) is a prominent air pollutant that is harmful to both the environment and human health. Conventional NO2 sensors that are designed to operate at room temperature often...


2021 ◽  
Author(s):  
Lifang Qi ◽  
Yao Le ◽  
Chao Wang ◽  
Rui Lei ◽  
Tian Wu

Self-assembling ultrathin active δ-MnO2 nanosheets and Mn3O4 octahedrons into hierarchical texture enhances room-temperature formaldehyde oxidation at a low-level of Pt.


2021 ◽  
Vol 6 (32) ◽  
pp. 8338-8344
Author(s):  
Xingyan Shao ◽  
Shuo Wang ◽  
Leqi Hu ◽  
Tingting Liu ◽  
Xiaomei Wang ◽  
...  

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