Highly Sensitive and Stable Humidity Nanosensors Based on LiCl Doped TiO2 Electrospun Nanofibers

Alan G. MacDiarmid Institute, Jilin University, Chang Chun 130012, PR China.
Journal of the American Chemical Society (Impact Factor: 11.44). 05/2008; 130(15):5036-7. DOI: 10.1021/ja800176s
Source: PubMed

ABSTRACT A new type of humidity nanosensor based on LiCl-doped TiO2 nanofibers with poly(vinyl pyrrolidone) (PVP) nanofibers as sacrificial template has been fabricated through electrospinning and calcination. The sensor exhibited excellent sensing characteristics, such as ultrafast response and recovery times, good reproducibility, linearity, and environmental stability, which are of importance for applications in humidity monitoring and control.

Download full-text


Available from: Zhenyu Li, Jul 23, 2014
1 Follower
  • Source
    • "In addition, the electrospinning method is incredibly effective for low-cost mass production with the minimal usage of materials, which makes it the most suitable method for industrial applications on the commercial scale. For these reasons, electrospun NFs have been employed in a diverse range of sensing materials [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14]. Possessing a wide bandgap (3.37 eV) with a large exciton energy (60 meV) [15], ZnO NFs-based semiconductors are one of the most promising sensing materials and have been extensively studied for the past several years [16] [17] [18]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We have fabricated sensors with reduced graphene oxide (RGO) nanosheets (NSs)-loaded ZnO nanofibers (NFs) via an electrospinning method. The RGO NSs-loaded ZnO NFs were comprised of nanograins with an average diameter of 20 nm. Transmission electron microscopy and X-ray diffraction both revealed the presence of RGO NSs in the ZnO NFs. The sensing properties of RGO NSs-loaded ZnO NFs were examined after exposure to various gases, including O2, SO2, NO2, CO, C6H6, and C2H5OH. The sensor responses showed a bell-shaped behavior with respect to the weight ratio of RGO NSs. It is remarkable that our sensors exhibited significantly higher responses than pure ZnO NFs. We propose a novel hybrid sensing mechanism for the drastic improvement in the sensing behavior that is caused by loading RGO NSs into ZnO NFs. This hybrid sensing mechanism combines the resistance modulation of ZnO/ZnO homointerfaces and RGO-NSs/ZnO heterointerfaces in addition to the radial modulation of the surface depletion layer of ZnO NFs. In the heterointerfaces, the creation of local heterojunctions plays a significant role in raising the sensitivity of RGO-loaded ZnO NFs.
    Sensors and Actuators B Chemical 08/2015; DOI:10.1016/j.snb.2015.07.120 · 4.29 Impact Factor
  • Source
    • "Molecular structure of PPI used in this work and the schematic illustration for the whole colorimetric and fluorescent detection of HCl gas. membranes with large surface area-to-volume ratio have great potentiality for improving sensing performance [34] [35] [36] [37] [38] [39] [40]. Thus, in this work, combining the merits of colorimetric and sensitive fluorescent properties of porphyrin with super thermal stability of polyimide, a nanofibrous membrane of PPI was used as an effective sensory material for the detection of trace HCl gas. "
    [Show abstract] [Hide abstract]
    ABSTRACT: A novel sensor fabricated from the nanofibrous membrane of porphyrinated polyimide (PPI) for the rapid detection of trace amount of hydrogen chloride (HCl) gas is described. Covalently bonding of the porphyrin fluorophores into polyimide main chains overcomes the disadvantage of porphyrin aggregation and improves the physicochemical stability of polyimide simultaneously. The dual chromo- and fluorogenic responses of the nanofibrous membrane upon exposure to HCl gas are interpreted in terms of the out-of-plane distortion of porphyrin macrocycle, which ultimately affects its optical properties. UV–vis and fluorescence spectroscopies were used to further study the protonation of porphyrin moieties in polyimide. With large amount of available surface area and hence good gas accessibility, the nanofibrous membrane of porphyrinated polyimide shows unusually high sensitivity and fast response time in sensing application. An apparent binding affinity constant of (1.05±0.23)×104Lmol−1 was calculated from surface plasmon resonance (SPR) analysis, confirming that the porphyrinated nanofibrous membrane is an applicable material for constructing HCl-sensitive gas sensor.
    Sensors and Actuators B Chemical 06/2010; 148(1):233-239. DOI:10.1016/j.snb.2010.05.029 · 4.29 Impact Factor
  • Source
    • "Cr 2 O 3 -sensitized ZnO (C-s-Z) composite nanofibers are fabricated through electrospinning and followed by calcination. In a typical procedure [18], 0.32 g of zinc nitrate and certain amount of chromium nitrate were added into a mixed solvent of N,Ndimethylformamide/ethanol containing a little Triton X-100 as surfactant in a glove box under vigorous stirring for 6 h. Subsequently , 0.6 g of PVP was added into the above solution under Fig. 1. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Certain amount of Cr2O3 has been in situ added to ZnO nanofibers during the electrospinning process and subsequent calcination to form Cr2O3-sensitized ZnO (C-s-Z) nanofibers. The morphology and structure of the as-prepared nanofibers have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS) and X-ray diffraction (XRD). The effect of the Cr2O3 component in C-s-Z nanofibers on the gas sensing properties has been evaluated by the responses to ethanol vapor. The results have showed that the C-s-Z nanofibers containing 4.5 wt% Cr2O3 exhibit the best sensing properties to ethanol vapor. The response to 1 ppm ethanol vapor is as high as 3.6, and the response and recovery time are about 1 and 5 s, respectively. In addition, the as-prepared sensors exhibit excellent selectivity and stability. These results indicate that the C-s-Z electrospun composite nanofibers can be used in fabricating high performance gas sensors.
    Sensors and Actuators B Chemical 01/2010; 143(2):754–758. DOI:10.1016/j.snb.2009.10.016 · 4.29 Impact Factor
Show more