- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Ordered mesoporous WO3/ZnO nanocomposites with isotype heterojunctions for sensitive detection of NO2
摘要： Ordered mesoporous WO3 nanocrystals have been successfully synthesized by a hydrothermal method using mesoporous silica of KIT-6 as a template and phosphotungstic acid as a precursor of WO3. The structure, morphology, and specific surface of WO3 nanocrystals were systematically characterized by XRD, SAXS, HR-TEM, and BET. To improve the sensing properties of WO3 to NO2, a series of different ZnO amounts were loaded on the mesoporous WO3 to construct nanocomposites with n–n heterojunction for the fabrication of NO2 sensors. The gas-sensing behaviors show that the sensor based on WO3/5 wt% ZnO composite to 1 ppm of NO2 not only exhibits the high response, but also has good selectivity and stability at operating temperature of 150 oC, which can be contributed to the large specific surface and porous channels provided by mesoporous structures, and the formation of n–n heterojunctions at interface between both oxides.
关键词： NO2 sensor.,ZnO,Mesoporous WO3,n–n isotype heterojunction
更新于2025-09-23 15:23:52
-
Laser-Writing of Janus Graphene/Kevlar Textile for Intelligent Protective Clothing
摘要： Protective clothing plays a vital role in safety and security. Traditional protective clothing can protect human body from physical injure. It is highly desired if modern wearable electronics can be integrated into traditional protection suit to endow it with versatile smart functions. However, it is still challenging to integrate electronics into clothing through a practical approach while keeping the intrinsic flexibility and breathability of textiles. In this work, we realized the direct writing of laser-induced graphene (LIG) on Kevlar textile in air and demonstrated the applications the as-prepared Janus graphene/Kevlar textile in intelligent protective clothing. The C=O and N?C bonds in Kevlar were broken and the remaining carbon atoms were reorganized into graphene, which can be ascribed to photothermal effect induced by the laser irradiation. Proof-of-concept devices based on the prepared graphene/Kevlar textile, including flexible Zn-air batteries, electrocardiogram electrodes, and NO2 sensors, were demonstrated. Furtherly, we fabricated a self-powered and intelligent protective clothing based on the graphene/Kevlar textile. The laser induced direct writing of graphene from commercial textiles in air conditions provides a versatile and rapid route for the fabrication of textile electronics.
关键词： laser-induced graphene,Kevlar textile,NO2 sensor,textile electronics,photothermal effect
更新于2025-09-23 15:19:57
-
Visible light enhanced black NiO sensors for ppb-level NO2 detection at room temperature
摘要： Although extensive studies have been carried out on n-type semiconductors for room-temperature gas sensor applications, some intrinsic problems remain. Therefore, other interesting attempts should be adopted to solve these issues, like p-type semiconductors. Previous studies have demonstrated that p-type semiconductor gas sensors exhibit better selectivity and less humidity dependence due to the distinctive oxygen adsorption and surface reactivity. Visible light is used as the external activation source to accelerate the sensing kinetics instead of heating. Stoichiometric NiO cannot absorb visible lights. Inspired by the works of black TiO2, we adopted three methods to prepare black NiO. XPS characterizations reveal that the presence of Ni3+ ions leads to the formation of black NiO. However, not all black NiO samples show good responses to NO2 at room temperature. Three main routes: synthesizing specific morphology with large specific surface area and porosity, introduction of Ni3+ ions and oxygen vacancies, are needed to get the enhanced sensing performance. The black NiO samples with large specific surface area and oxygen vacancies and Ni3+ ions show obvious response towards ppb-level NO2 with visible light irradiation at room temperature. Furthermore, light wavelength is found to play a vital role in the sensing characteristics, and blue light is the optimal choice. Different from traditional NiO sensors operated at high temperatures exhibiting superior response to reducing gases, the black NiO show excellent selectivity towards oxidizing gas, ppb-level NO2, at room temperature illuminated by blue light. In contrast with n-type semiconductors, the black NiO samples also exhibit less humidity dependence.
关键词： Room temperature,NO2 sensor,NiO,Visible light irradiation
更新于2025-09-09 09:28:46
-
Enhanced NO2 gas sensing of a single-layer MoS2 by photogating and piezo-phototronic effects
摘要： NO2 sensors with ultrahigh sensitivity are demanded for future electronic sensing systems. However, traditional sensors are considerably limited by the relative low sensitivity, high cost and complicated process. Here, we report a simply and reliable flexible NO2 sensor based on single-layer MoS2. The flexible sensor exhibits high sensitivity to NO2 gas due to ultra-large specific surface area and the nature of two-dimensional (2D) semiconductor. When the NO2 is 400 ppb (parts per billion), compared with the dark and strain-free conditions, the sensitivity of the single-layer sensor is enhanced to 671% with a 625 nm red light-emitting diode (LED) illumination of 4 mW/cm2 power under 0.67% tensile strain. More important, the response time is dramatically reduced to ～16 s and it only needs ～65 s to complete 90% recovery. A theoretical model is proposed to discuss the microscopic mechanisms. We find that the remarkable sensing characteristics are the result of coupling among piezoelectricity, photoeletricity and adsorption-desorption induced charges transfer in the single-layer MoS2 Schottky junction based device. Our work opens up the way to further enhancements in the sensitivity of gas sensor based on single-layer MoS2 by introducing photogating and piezo-phototronic effects in mesoscopic systems.
关键词： photogating effect,single-layer MoS2,ultrahigh sensitivity,flexible NO2 sensor,piezo-phototronic effect
更新于2025-09-04 15:30:14