sensor response of sol–gel multiwalled carbon nanotubes-tio2 composites

... (left) and TiO 2 –MWCNT composites (right). Please cite this article in press as: M. Sánchez, M.E. Rincón, Sensor response of sol–gel multiwalled carbon nanotubes-TiO 2 composites deposited by ... reserved. doi:10.1016/j.snb.2009.04.006 Please cite this article in press as: M. Sánchez, M.E. Rincón, Sensor response of sol–gel multiwalled carbon nanotubes-TiO 2 comp...

Ngày tải lên: 20/03/2014, 13:07

... (SEM). The performance of sensor devices, based on the WO 3 films, was investigated by a two-point measuring system capable of in situ conductivity determinations as a function of sensor temperature and ... response and recovery times of the sensors (see Fig. 5a), but there is a concomitant decrease of the sensitivity by more than two orders of magnitude compared to the case...

Ngày tải lên: 19/03/2014, 16:48

... the financial support of the project. The partial support of the High Technology Organization (HTO) of the Ministry of Industries and Mines is appreciated. The assistance of Mr. S. Rafiei for XPS ... gold concentrations of 0, 3.2 and 6.4 mol%. Optical properties of the samples were studied by UV–visible spectrophotometry in a range of 300–1100 nm. The optical density spectra of...

Ngày tải lên: 20/03/2014, 13:04

... sensing characteristics of the thin film sensor to trimethylamine were measured. A low-temperature, high sensitivity, excellent selectivity, quick response and recover of thin film sensors to trimethylamine ... analysis. To eliminate the effect of sample surface charging the shift of the XPS peak of carbon (C 1s whose binding energy is 284.6eV) was used. 2.3. Measurements of g...

Ngày tải lên: 20/03/2014, 13:12

Ngày tải lên: 01/04/2014, 10:40

... theoretical expression, TEM etc. The TEM images of samples show that the mean sizes of QDs are 4 nm. The mean sizes of QDs are smaller than that of other methods and arranging from 2 to 3.6 nm. ... wavelength of the first excitonic absorption peak (Table 2). The deviation of the peaks in absorption spectra is about 50 nm, which may be due to the difference of surface state...

Ngày tải lên: 14/03/2014, 13:20

... having a response of 2.3 and a time response of 60 s to 1 ppm of NO 2 as shown in Fig. 5. 4.5. Ethanol vapor sensing The sensors where exposed to 100±600 ppm of ethanol and to 10±30 ppm of CO to ... a negligible response to CO, which is desirable. Furthermore, commercialized alcohol sensors [16] have a response of 10± 500 ppm (0.05%) of ethanol. Fig. 4. CO and NO 2 resp...

Ngày tải lên: 19/03/2014, 16:47

... NH 3 . The gas response is defined as (R gas − R air )/R air , where R air is the resistance of sensor in air and R gas is the steady resistance of sensor in the presence of a tested gas. The response ... NH 3 decreased by a factor of 2–3 during 30 days. Therefore, the lack of long-term stability of the fabricated sensor was of concern. The resistance changes of the s...

Ngày tải lên: 20/03/2014, 13:04

... of aggregates of nanorods of ∼10 nm in diameter. The nanocrystalline TiO 2 thus prepared appears to have an engraved surface morphology and consists mainly of the anatase and mi- nor amount of ... reaction encourages a basic sol–gel reaction sys- tem; this allows the surface of TiO 2 to be negatively charged because the pH of the sol–gel system is now above the IEP of TiO...

Ngày tải lên: 20/03/2014, 13:07

... treatment of the precursor at 400 ◦ C in air resulted in the formation of WO 3 /TiO 2 nanocomposites with a particle size of about 60nm. The c-axis parameter of TiO 2 in the WO 3 /TiO 2 nanocomposites, ... 1. DTA curves of the precursor with different amount of WO 3 (a) 10 wt%, (b) 20wt% and (c) 40 wt%. Fig. 2. XRD patterns of the WO 3 /TiO 2 nanocomposites with different amount...

Ngày tải lên: 20/03/2014, 13:08