Facile synthesis and gas sensing properties of In2O3–WO3 heterojunction nanofibers

Enhanced sensitive and selective xylene sensors using W-doped NiO nanotubes

“…This process maybe helps stabilizing the microstructure and possibly pre-aging the sensing materials more effectively to achieve improved long term stability of sensors. The gas sensing properties of sensors based on pure and W-doped NiO nanotubes were measured by a static gas sensing characterization system, as diagrammed in our previous works [6,35]: first, atmospheric air was introduced into a glass chamber, and then a desired concentration of tested gas was injected into the chamber by a micro-injector, the concentration of volatile organic compounds (VOC) was obtained by the static liquid gas distribution method [36], which was calculated by formula (2).…”

“…Therefore, the quantitative analysis of xylene is of critical importance to personal safety and environmental sustainability. So far, gas chromatography-mass spectrometry, fluorescence spectroscopy and proton transfer reaction-mass spectrometry can be utilized to analyze the concentration of VOCs [5,6]. However, the high cost, unportable and complicated operation hinder the application of such equipments at home.…”

Porous silicon filled with Pd/WO3–ZnO composite thin film for enhanced H2 gas-sensing performance

“…55 When two dissimilar materials WO 3 and ZnO formed an electrical connection at the interface, then the electrons will start to ow from high energy conduction band to the lower energy conduction band (from WO 3 to ZnO) until the Fermi levels have equilibrated. Due to lower work function of WO 3 , a depletion region is created towards WO 3 at the n-n heterostructures interface whereas an accumulation region is formed towards ZnO caused by transfer the electrons from WO 3 to ZnO.…”

“…56 In ambient air, the oxygen species adsorbed at the grain boundaries of WO 3 and ZnO and shield the WO 3 /ZnO heterojunctions such that the conducting electrons being trapped, and the composite layer become more resistive. 55,57 This results to create the barrier height at the WO 3 /ZnO heterojunction. Thereaer, the exposed H 2 gas molecules will reduce the adsorbed oxygen species on the surface.…”

Facile synthesis and gas sensing properties of La2O3–WO3 nanofibers

“…Because of their amazing properties such as large surface area to volume ratio, easy control dimension and superior mechanical performance, the 1D functional nanomaterials offer tremendous impact in the field of optics, lithium ion batteries, solar cells, electronics, gas sensors, and so on [5][6][7]. Various methods have been developed to fabricate 1D nanostructures, such as laser assisted catalytic growth, metal organic chemical vapor deposition (MOCVD), thermal evaporation and electrospinning [8,9]. Among these methods, electrospinning seems to be one of the most simple, versatile and low-cost methods for producing organic or inorganic nanofibers [8][9][10].…”