e. when the particle size decreased, the band-gap energy increased.ZnO is an interesting chemically and thermally stable n-type semiconductor of wurtzite structure with a large-band selleck chemicals Ruxolitinib gap energy of 3.37 eV at low temperature and 3.3 eV at room temperature [3�C6], and with high sensitivity to toxic and combustible gases. It is sensitive to many gases at moderate temperature, especially H2 gas [7�C12]. For comparison with Inhibitors,Modulators,Libraries the same doping material there were many reports of other preparation methods. Xu et al. [7] prepared pure ZnO powder by chemical precipitation. The response characteristics of 0.5 wt% Pt/ZnO nanoparticles to 0.2% H2 in air at 330 ��C was reported with the sensitivity of 2. Moreover, Rout et al. [9] reported ZnO nanowires/nanotubes prepared by electrochemical deposition on alumina membranes.

The response characteristics for 1 at.% Pt/ZnO nanoparticles Inhibitors,Modulators,Libraries were obtained. The sensitivity of ZnO nanowires without and with Pt impregnation for 1,000 ppm of H2 were 43 and 825 at 150 ��C, respectively, indicating the enhancement in sensitivity by incorporating Pt into the ZnO nanowires. The response time for the as-prepared and the Pt-impregnated ZnO were 54 and 42 s respectively with the recovering times of 5 and 4 s respectively. In addition, Wang et al. [10] reported ZnO nanorods deposited by Molecular Beam Epitaxy (MBE) and detection of hydrogen at room temperature with catalyst-coated multiple ZnO nanorods. The Pt metal catalyst coating deposited on multiple ZnO nanorods were compared for their effectiveness in enhancing sensitivity for detecting hydrogen at room temperature.

Pt-coated nanorods showed a relative response of up to 8% in room temperature Inhibitors,Modulators,Libraries resistance upon exposure to a hydrogen concentration in N2 of 500 ppm. Tien et al. [11] reported that ZnO nanorods were deposited by Molecular Beam Epitaxy (MBE) and hydrogen sensing at room temperature with Pt-coated ZnO thin films and nanorods. A comparison of the sensitivities was reported for detecting hydrogen with Pt-coated single ZnO nanorods and thin films. The Pt-coated single nanorods showed a current response of approximately a factor of 3 larger at room temperature upon exposure to 500 ppm H2 in N2 than the thin films of as-prepared ZnO. For comparison with other Inhibitors,Modulators,Libraries doping materials, Xu et al. [7] reported that a Ru-doped ZnO gas sensor showed the selectivity of 0.

2% H2 at 230 ��C and 400 ��C were 6 and 2, respectively. The Rh-doped ZnO gas sensor had good gas selectivity for 0.2% H2 of 115 at 300 ��C. A Ag-doped ZnO gas sensor showed characteristic response of 9 for 0.2% H2 at 400 ��C. A summary comparing H2 sensing Carfilzomib with metal-doped ZnO prepared by several synthetic methods is shown in Table selleck chem 1. ZnO is one of the most widely applied oxide-gas sensor. ZnO gas sensing materials owe to their high chemical stability, low cost, and good flexibility in fabrication.