KEY ENGINEERING MATERIALS
·
2016
·
IF 0
Jian Wu,Cheng Zhang,Jin Feng Xia,Dan Yu Jiang
In this study, Yttria-stabilized zirconia (YSZ) electrochemical sensors attached with the WS2 sensing electrode (SE) were fabricated and examined for NO2 sensing properties. Due to its internal stratiform structure, surface and edge of the lamella have high chemical activity, WS2 was used as a kind of highly efficient catalyst. WS2 was partial oxidated to WO3 at 400°C, and with the increment of temperature, oxidation will accelerate. The ΔEMF to 500 ppm NO2 was as high as 125mv at 400°C, while the value of WO3-based sensor was as small as 10 mv in the same condition. These WS2-attached devices gave a linear correlation between EMF and the logarithm of NO2 concentration from 30 to 500 ppm in the temperature range 350–500°C. The response time of the device is about 1 min at 400°C.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
ACS Applied Nano Materials
·
2023
·
IF 5.9
Weiqi Wang,Jiamu Cao,Rongji Zhang,Huaxin Xiu,Yufeng Zhang
Although SnO2 nanomaterials have been leading components of semiconductor gas sensors, their long-standing challenges of high working temperatures limit their practical application for ultralow-power-consumption room-temperature sensing. In this study, Au and Pt bimetallic nanoparticles were used to fabricate a MoS2/AuPt/SnO2 nanocomposite device by interfacially engineering a MoS2/SnO2 nanostructure. Owing to the unique structure and electrical properties, the as-fabricated MoS2/AuPt/SnO2 device exhibits a remarkable sensing response (2.22), short response time (20 s), and excellent baseline recovery (8 s) to 10 ppm NO2 gas at 23 ± 2 °C. Meanwhile, the MoS2/AuPt/SnO2 device possesses high sensitivity, a low detection limit (20 ppb), commendable reversibility, appreciable stability, and excellent selectivity against ammonia, carbon monoxide, ethanol, isopropanol, and acetone gases. The superior sensing characteristics of the MoS2/AuPt/SnO2 nanocomposite device are attributed to the modulation effect of the Schottky junction and p–n heterojunction on the potential barrier, highly efficient interfacial electron transport, and edge-enriched structure, which provide abundant active adsorption sites. This work will advance the evolution of room-temperature gas-sensitive nanomaterials and render them promising for applications in ultralow power-integrated sensors.
研究领域:
材料科学
·
纳米技术
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
THIN SOLID FILMS
·
2016
·
IF 1.761
Min Li,Wenkai Zhang,Gang Shao,Hao Kan,Zhilong Song,Songman Xu,Haoxiong Yu,Shenglin Jiang,Jingting Luo,Huan Liu
Colloidal quantum dots (CQDs) are emerging as ideal building blocks for the development of sensitive and low-cost gas sensors because of their large surface area and solution processability. So far, the construction of CQD gas sensor is limited to lab-scale, batch-processing methods such as spin coating . Here, we demonstrated highly sensitive and fast-response CQD gas sensors through a room-temperature spray-coating route in ambient air. Unlike the spin-coating process, a porous film morphology could be achieved by the spray-coating of ultrasmall PbS CQDs (4.0 nm in diameter) on the alumina ceramic substrates , possibly explaining their superior gas-sensing performance. Moreover, we investigated the effect of the dispersing solvent on the spray-coated PbS CQD films and found that organic solvents with lower boiling point were preferred in producing porous and sensitive CQD films. The response of the optimal gas sensors toward 50 ppm of NO 2 at room temperature was high as 44, with response and recovery times short as 1 s and 28 s, respectively. The enhanced gas-sensing capabilities, coupled with the promise for mass production at room temperature, make the spray-coated CQD gas sensors very attractive in the future gas-sensing technology.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 16
·2289
·
IF 5.3
Zhenyu Wang,Haizhen Ding,Xuefeng Liu,Jing Zhao
Semiconductor oxide gas sensors have important applications in environmental protection, domestic health, and other fields. Research has shown that designing the morphology of sensitive materials can effectively improve the sensing characteristics of sensors. In this paper, by controlling the solvothermal reaction time, a unique hexagonal flower-like structure of In2O3materials consisting of cuboid nanorods with a side length of 100–300 nm was prepared. The characterization results indicated that with the increase in reaction time, the materials exhibited significant morphological evolution. When the solvent heating time is 5 h, the flower-like structure is basically composed of hexagonal nanosheets with a thickness of several hundred nanometers and a side length of several micrometers. With the increase in reaction time, the apex angles of the nano sheets gradually become obtuse, and, finally, with the Ostwald ripening process, they become cuboid nanorods with side lengths of 100–300 nanometers, forming unique micro-flowers. Among them, the material prepared with a reaction time of 20 h has good sensing performance for NO2, exhibiting low operating temperature and detection limit, good selectivity, repeatability, and long-term stability, thus suggesting a good application prospect.Keywords:In2O3;micro-flowers;morphological evolution;NO2sensor;solvothermal
研究领域:
材料科学
·
环境科学
·
化学传感器
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2020
·
IF 2.87
Weisi He,Yanhong Zhao,Yuhua Xiong
In this work, a novel bilayer polyaniline–WO3 (PANI–WO3) thin film on the fluorine-doped tin oxide (FTO) glass substrate was prepared by hydrothermal synthesis and in situ chemical oxidative polymerization methods. Until now, no one has ever made attempts to use the PANI–WO3 composite on the FTO glass substrate to detect NO2 gas. The composite showed excellent sensing performance for NO2 detection at an operation temperature of 50 °C and a detection limit of 2 ppm. With regard to the PANI–WO3 hybrid, the response value for NO2 at 30 ppm is 60.19 and is three times higher than that for pure WO3 at 50 °C. Besides, the PANI–WO3 hybrid had excellent stability. The improvement of gas sensing was assigned to the creation of p–n heterojunctions between p-type PANI and n-type WO3, larger specific surface, increase of oxygen vacancies, and a wide conduction channel provided by PANI.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2024
·
IF 3.5
Zhiwei Lu,Xiaoxiao Pei,Tingting Wang,Kewei Gu,Nan Yu,Mingsong Wang,Junli Wang
Tin dioxide (SnO2)-based electronic materials and gas sensors have attracted extensive attention from academia and industry. Herein we report the preparation of two-dimensional (2D) porous SnO2 flakes by thermal oxidation of 2D SnS flakes that serve as a self-sacrificial template. An oxidation-enabled, temperature-dependent matter conversion from SnS through three-phase SnS–SnS2–SnO2 (400 °C) and two-phase SnS2–SnO2 (600 °C) to pure-phase SnO2 (≥800 °C) is disclosed by means of combined XRD, TG-DSC and XPS studies. Meanwhile, the associated chemical reactions and the mass and heat changes during this solid-state conversion process are clarified. The as-prepared 2D SnO2 flakes exhibit structural porosity with tunable pore sizes and crystallite sizes/crystallinity, resulting in superior potential for NO2 sensing. At the optimized operating temperature of 200 °C, the prototype gas sensors made of porous SnO2 flakes show competitive sensing parameters in a broad NO2 concentration range of 50 ppb–10 ppm in terms of high response, faster response/recovery speeds, and good selectivity and stability. A sensing mechanism involving the adsorption and desorption of NO2/O2 molecules and the possible surface reactions is further rationalized for the SnO2 NO2 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
SENSORS
·
2021
·Vol. 21
·期 24
·8269
·
IF 3.576
Kai Sun,Guanghui Zhan,Hande Chen,Shiwei Lin
CeO2/ZnO-heterojunction-nanorod-array-based chemiresistive sensors were studied for their low-operating-temperature and gas-detecting characteristics. Arrays of CeO2/ZnO heterojunction nanorods were synthesized using anodic electrodeposition coating followed by hydrothermal treatment. The sensor based on this CeO2/ZnO heterojunction demonstrated a much higher sensitivity to NO2at a low operating temperature (120 °C) than the pure-ZnO-based sensor. Moreover, even at room temperature (RT, 25 °C) the CeO2/ZnO-heterojunction-based sensor responds linearly and rapidly to NO2. This sensor’s reaction to interfering gases was substantially less than that of NO2, suggesting exceptional selectivity. Experimental results revealed that the enhanced gas-sensing performance at the low operating temperature of the CeO2/ZnO heterojunction due to the built-in field formed after the construction of heterojunctions provides additional carriers for ZnO. Thanks to more carriers in the ZnO conduction band, more oxygen and target gases can be adsorbed. This explains the enhanced gas sensitivity of the CeO2/ZnO heterojunction at low operating temperatures.Keywords:gas sensor;NO2detection;heterojunction;low operating temperature;CeO2
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 89
·73083-73090
·
IF 3.84
Kuiyi You,Renjie Deng,Jian Jian,Pingle Liu,Qiuhong Ai,He’an Luo
Developing a new environmentally friendly process for benzene nitration to nitrobenzene has been highly desirable for a long time. In this work, NO2 was used as a nitration agent to replace traditional nitric acid, and different mesoporous SiO2 and their supported heteropoly acid (salt) were employed to catalyze benzene nitration to nitrobenzene. Several typical catalysts were characterized using XRD, BET and FT-IR, and the acid amounts of the various catalysts were determined. The effects of various factors such as different catalysts, the molar ratio of benzene to NO2, reaction temperature, reaction time, HPW loading, the acid amounts of the catalyst and the reuse of the catalyst on the nitration reaction have also been systematically examined. The results indicate that the supported HPW/MCM-41 catalysts exhibit a remarkably synergistic catalytic performance on the nitration reaction of benzene to nitrobenzene. In particular, the 50%HPW/MCM-41 catalyst gives the best results with 73.4% benzene conversion and 98.8% selectivity to nitrobenzene under the optimal reaction conditions. Moreover, the mesoporous structure of MCM-41 was retained under the high loading of HPW. The possible reaction mechanism for the nitration reaction of benzene with NO2 over HPW/MCM-41 is suggested in the present work. This method provides a promising strategy for the preparation of nitro-aromatic compounds from a catalytic nitration reaction by using NO2 as the nitration reagent.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2020
·Vol. 26
·期 17
·3870-3876
·
IF 4.857
Xiaoshan Wang,Yao Liu,Jie Dai,Qian Chen,Xiao Huang,Wei Huang
Graphical By taking advantage of the crystal phase dependent electronic property of SnSe x based materials, SnSe( x %)/SnSe 2 (100− x %) p–n heterostructures were synthesized via a facile one-step colloidal method, and the SnSe(50 %)/SnSe 2 (50 %) based sensor exhibited much improved sensing performance due to the formation of p–n hetero-junctions. The formation of semiconductor heterostructures is an effective approach to achieve high performance in electrical gas sensing. However, such heterostructures are usually prepared via multi-step procedures. In this contribution, by taking advantage of the crystal phase-dependent electronic property of SnSe x based materials, we report a one-step colloid method for the preparation of SnSe( x %)/SnSe 2 (100− x %) p–n heterostructures, with x ≈30, 50, and 70. The obtained materials with solution processability were successfully fabricated into NO 2 sensors. Among them, the SnSe(50 %)/SnSe 2 (50 %) based sensor with an active layer thickness of 2 μm exhibited the highest sensitivity to NO 2 (30 % at 0.1 ppm) with a limit of detection (LOD) down to 69 ppb at room temperature (25 °C). This was mainly attributed to the formation of p–n junctions that allowed for gas-induced modification of the junction barriers. Under 405 nm laser illumination, the sensor performance was further enhanced, exhibiting a 3.5 times increased response toward 0.1 ppm NO 2 , along with a recovery time of 4.6 min.
研究领域:
材料科学
·
化学传感器
·
纳米技术
✓ 已验证
DOI
高影响因子
TALANTA
·
2024
·
IF 5.6
Huimin Yang,Yazhou Yang,Chaofan Ma,Qirui Wu,Jiahong Tang,Chaoqi Zhu,Xiaoxia Wang,Dawen Zeng
NO 2 is a hazardous gas extremely harmful to the ecosystem and human health, so effective detection of NO 2 is critical. SnSe 2 is a promising candidate for gas sensors owing to its unique layered configuration that facilitates the diffusion of gas molecules. Here, ultrathin self–assembled nanoflowers F–SnSe 2 rich in defects were synthesized by a simple solvothermal method. It exhibits excellent gas sensing performances for NO 2 at room temperature (25 °C), with a high gas sensing response of 8.6 for 1 ppm NO 2 and a lower detection limit as low as 200 ppb, capable of sensitively detecting ppb–level NO 2 . DFT calculations revealed that the presence of Se vacancies assists the central Sn atoms to break through the shielding effect of the surface Se atoms and become exposed active sites. The higher reactivity leads to more charge transfer and higher adsorption energy , which strongly promoted the adsorption of NO 2 . This work verifies the important role of vacancies for the exposed active sites and provides new guidance for defect engineering to modulate the gas sensing performances of SnSe 2 .
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 8
·1413
·
IF 5.3
Mingjia Bai,Chaoyang Li,Xiaojun Zhao,Qingji Wang,Qinhe Pan
ZnO is a wide band gap semiconductor metal oxide that not only has excellent electrical properties but also shows excellent gas-sensitive properties and is a promising material for the development of NO2sensors. However, the current ZnO-based gas sensors usually operate at high temperatures, which greatly increases the energy consumption of the sensors and is not conducive to practical applications. Therefore, there is a need to improve the gas sensitivity and practicality of ZnO-based gas sensors. In this study, three-dimensional sheet-flower ZnO was successfully synthesized at 60 °C by a simple water bath method and modulated by different malic acid concentrations. The phase formation, surface morphology, and elemental composition of the prepared samples were studied by various characterization techniques. The gas sensor based on sheet-flower ZnO has a high response value to NO2without any modification. The optimal operating temperature is 125 °C, and the response value to 1 ppm NO2is 125. At the same time, the sensor also has a lower detection limit (100 ppb), good selectivity, and good stability, showing excellent sensing performance. In the future, water bath-based methods are expected to prepare other metal oxide materials with unique structures.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Guangyuan Chen,Linzhen Wu,Zeru Wang,Ruixi Liu,Chuan Tan,Yi Tan,Yawen Liu,Miaomiao He,Hao Zhang,Yikun Huang,Jiongzhi Zhu,Tao Duan,Lin Zhu
The capture of radioactive gaseous iodine is essential for the sustainable development of nuclear energy and the long-term safe supply of nuclear fuel. However, the presence of nitrogen oxides in the exhaust gas generated during spent fuel reprocessing poses significant challenges to the stability of iodine adsorbents. It is crucial to consider the impact of NOx on the structure and adsorption performance of the materials. We report here the development of an aluminum-based metal–organic framework (MOF), CAU-1, engineered for efficient iodine capture. Synthesized through a cost-effective and straightforward method, CAU-1 exhibits excellent structural stability and robust adsorption performance, with a maximum iodine vapor adsorption capacity of 1277.18 mg/g at 130 °C and methyl iodide adsorption capacity of 533.10 mg/g, highlighting its potential for efficient iodine vapor removal. Notably, CAU-1 retains its structural integrity and iodine adsorption performance even in the presence of 5 % NO 2 , maintaining high adsorption capacities for I 2 (1129.41 mg/g) and CH 3 I (436.79 mg/g). Mechanistic analysis revealed the key role of the –NH 2 group in the iodine adsorption process. Additionally, co-adsorption studies with I 2 and NO 2 showed that CAU-1 can still capture iodine in the form of both I 2 and I 3 - in the presence of NO 2 . This study illustrates the potential of CAU-1 as an effective industrial adsorbent for removing iodine from NO 2 -containing gas streams.
研究领域:
材料科学
·
核能工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）