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
    [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
  • Source
    [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
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The humidity sensitive characteristics of sensors fabricated from pure ZnO nanofibers and LiCl-doped ZnO composite fibers by screen-printing on ceramic substrates with carbon interdigital electrodes have been investigated. The best result is obtained for 1.2 wt% LiCl-doped sample, which exhibits high humidity sensitivity, rapid response and recovery, small hysteresis, excellent linearity, and good reproducibility. The impedance of the sensor varies more than four orders of magnitude during the whole relative humidity (RH) from 11 to 95%. The response time and recovery time of the sensor is about 3 and 6 s, respectively. These results make our product a good candidate in fabricating high performance humidity sensors.
    Sensors and Actuators B Chemical 09/2009; 141(2):404–409. DOI:10.1016/j.snb.2009.06.029