Here, a high sensitivity gas sensing ink based on sulfonated rGO (S-rGO) decorated with SnS2 is synthesized for room temperature NO2 and NH3 detection. This sensing ink demonstrated an excellent sensitivity to ppb-level NO2 (17% response to 125 ppb) and sub-ppm-level NH3 (11% response to 1 ppm). The unique absorption properties of SnS2 improve the sensitivity of S-rGO 4.2 and 55 times to NO2 and NH3, respectively. Besides, the superhydrophobicity of the SnS2 endows the sensor with exceptional immunity to high relative humidity (RH). Furthermore, the sensors exhibit negligible degradation to NO2 and less than 15% degradation to NH3 in a wide range of RH from 30 (ambient humidity) to 90%. More importantly, the obtained full-written ink can be applied to common substrates, such as glass, clothes, and paper, and maintain excellent performance after being bent and twisted by 180°.
Icing and frosting bring many disadvantages to people's life. Ice accumulation will affect the flight safety of aircraft, delay the rocket launch mission, deform transmission lines and power networks, cause transportation obstacles, and even produce major economic problems and personal safety problems. Conventional anti-icing and de-icing methods are often costly, inefficient, or environmentally harmful. Superhydrophobic technology, which uses the intrinsic properties of materials to delay icing and significantly reduces the ice adhesion between ice and substrate, is a promising anti-icing and deicing technology. In this paper, firstly, the wetting phenomenon of solid surface and ice nucleation mechanism are introduced. It should be indicatedthat superhydrophobic surfaces face many problems such as the itswettability can be changed with decreasing the temperature and increasing the relative humidity, poor stability and mechanical robustness, and lack of facile and large-scale fabrication methods. Secondly, the research progress of superhydrophobic anti-icing and de-icing materials, stable and mechanically robust superhydrophobic surfaces, fabrication of superhydrophobic surfaces and multifunctional anti-icing and de-icing superhydrophobic materials are reviewed and analyzed.Finally, manyapplications of anti-icing and de-icing superhydrophobic materials in practical engineering are concluded and summarized. On this basis, the development trends and prospects of anti-icing and de-icing superhydrophobic materials are discussed.
High quality ZnO thin films have been grown on a Si(100) substrate by plasma enhanced chemical vapor deposition using a zinc organic source [Zn(C2H5)2] and carbon dioxide (CO2) gas mixtures at the low temperature of 180 °C. The dependence of ZnO thin film quality on the gas flow rate ratio of Zn(C2H5)2 to CO2 (GFRRZC) is studied by using x-ray diffraction (XRD), optical absorption (OA) spectra, and cathodoluminescence (CL) spectra. High quality ZnO thin films with a c-axis-oriented wurtzite structure are obtained when the GFRRZC is 0.33. XRD shows that the full width at half maximum of (0002) ZnO located at 34.42° is about 0.2°. At room temperature, a pronounced free exciton absorption peak around 365 nm is clearly observed. Also, a strong free exciton emission without deep level defect emission is observed around 385 nm, and its temperature dependence is studied from the photoluminescence spectra. These observations indicate the formation of a high quality ZnO film. Additionally, nitridation of the Si surface caused by releasing NH3 plasma into the deposition chamber is an effective way to improve film quality.
A composite coating with a micro–nanoscale hierarchical structure, which has controllable wettability and adhesion behavior, is fabricated by a one-step method and shows an enhanced underwater self-sensing capability.
A superhydrophobic, heterogeneous open-cell graphene network is fabricated by an inverse drying method, and it has a controllable adhesion behavior and detection functions for multiple underwater motions.
Transition-metal dichalcogenides (TMDs) have gained intense interest for their outstanding optoelectronic and electrochemical characteristics, utilized in versatile applications such as gas sensors and photodetectors. However, TMD-based chemiresistors suffer from poor sensitivity at ppb-level detection, and the experimental detection limit fails to reach 1 ppb. Herein, SnS2 QD/graphene nanoheterostructures as functional flexible sensors are fabricated for NO2 gas and light detection at room temperature. The semiconductor type of the nanohybrids can be shifted between p-type and n-type by adjusting the proportion of the components, both of which exhibit excellent gas-sensing properties. The ppb-level NO2 detection is realized even under room temperature with superior sensitivity (860% to 125 ppb), fast response (114 s), and recovery (166 s). It also demonstrates ultrahigh sensitivity and broadband photodetection in the visible region. The photoresponsivity can reach upto 2.08 × 103 A/W under blue light illumination and under room temperature. Especially, the influence of light illumination of different wavelengths and intensities on gas-sensing performance is studied. Red light (1 mW/cm2) greatly enhances the sensitivity up to 5.1 folds, and the device performs obvious response to NO2 at concentrations as low as 1 ppb. Ab initio density functional theory calculation and band theories are applied to explain the interaction of the components and the effect of the light excitation inducing charge carriers on gas-sensing equilibrium.
A graphene-based gradient wrinkle strain sensor with a broad range and ultra-high sensitivity was fabricated by a simple pre-stretching method. It can be applied to the detection of full-range human body motions.
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