Characterization of nanocrystalline palladium for solid state gas sensor applications

Generation and Sizing of Particles for Aerosol-Based Nanotechnology

“…Doping the tin dioxide films with metal particles was shown to enhance the gas selectivity of the sensors Labeau et al 1993;Labeau et al 1994;Tadeev et al 1998;Renault et al 1999). The conductivity of nanostructured films and wires made of palladium nanoparticles have been shown to be very sensitive on the concentration of hydrogen in the overlying gas (Volkening et al 1995;Kovacik et al 2008). Recently, Teleki et al (2008) showed that Nb-and Cu-doped TiO2 structures can also be used for sensing carbon monoxide and ethanol.…”

Faster H recovery in Pd nanoparticle layer based Gd switchable mirrors: Size-induced geometric and electronic effects

“…Hydrogenation and in situ electrical measurement procedures and various characterization techniques used have been described elsewhere. 10,11 Figure 1͑i͒ and 1͑ii͒ shows the AFM images of Pd overlayer deposited on Gd polycrystalline films. The average lateral dimension of Pd nanoparticles estimated from the AFM images of the samples N1, N2, and N3 are 9 nm, 14 nm, and 26 nm, respectively.…”

“…[6][7][8] Studies on H interaction with Pd clusters have reported enhanced hydrogen diffusivity, increased reversibility of absorption kinetics, narrowed miscibility gap, and increased hydrogen solubility with reduction in nanoparticle size. 6,9,10 In various reports on switchable mirror applications, the switching kinetics and consequently the hydrogen uptake rate has been studied by varying the thickness of the Pd overlayer. 5,11,12 Pd forms well separated small clusters at lower thickness, which grow into a continuous film at higher thickness.…”

“…In earlier studies on Pd nanocrystalline layers, it has been shown that the rate-controlling step for H loading is the dissociative chemisorption, whereas during recovery, diffusion of H through Pd. 10 is the rate controlling step. It is also known that Pd-H interaction takes place predominantly at structural kinks, edges and corners at Pd surface.…”

Large arrays of chemo-mechanical nanoswitches for ultralow-power hydrogen sensing

“…As a sensitive material, palladium (Pd) is the most prominent material by far due to its highly catalytic surface and large hydrogen solubility [1]. Common sensors rely on changes in resistivity upon hydrogenation [2][3][4], charge separation at Pd-SiO 2 interfaces in MOS structures [5] or single bimorph cantilevers with capacitive or optical readout [6,7]. They mostly require active heating elements, which lead to high power consumption.…”