Monodisperse platinum nanoparticles with controlled size were synthesized by polyol synthesis and supported on γ-Al2O3, SiO2 and carbon nanotubes (CNT) by the colloid deposition method. The average size of Pt nanopar...Monodisperse platinum nanoparticles with controlled size were synthesized by polyol synthesis and supported on γ-Al2O3, SiO2 and carbon nanotubes (CNT) by the colloid deposition method. The average size of Pt nanoparticles in colloidal solutions and on supports were determined by TEM images and from XRD patterns. The size of Pt nanoparticles supported on SiO2 and CNT determined from XRD patterns is in a good agreement with size obtained from the TEM analyses. There were shown that no agglomeration and size changing of Pt nanoparticles on these supports were observed. All these findings illustrate that the method of colloid deposition allows one to obtain catalyst with monodisperse platinum nanoparticles of controlled size deposited on different supports without changing the nanoparticle’s size and morphology.展开更多
BiFeO3 (BFO) thin films were prepared on Pt(111)/TiO2/SiO2/Si(100) substrates by the pulsed-laser deposition (PLD) technique at a low temperature of 450℃. The XRD results indicate that the BFO thin films are of perov...BiFeO3 (BFO) thin films were prepared on Pt(111)/TiO2/SiO2/Si(100) substrates by the pulsed-laser deposition (PLD) technique at a low temperature of 450℃. The XRD results indicate that the BFO thin films are of perovskite structure with the presence of small amount of second phases. The oxygen pressures have great effect on the crystalline structures and dielectric properties of BFO thin films. The dielectric constant of the BFO thin films decreases with increasing oxygen pressures, achieving 186, 171 and 160 at the frequency of 104 Hz for the oxygen pressures of 0.666, 1.333 and 13.332 Pa, respectively. The BFO thin films prepared at the oxygen pressure of 0.666 Pa reveal a saturated hysteresis loop with the remanent polarization of 7.5 μC/cm2 and the coercive field of 176 kV/cm.展开更多
文摘Monodisperse platinum nanoparticles with controlled size were synthesized by polyol synthesis and supported on γ-Al2O3, SiO2 and carbon nanotubes (CNT) by the colloid deposition method. The average size of Pt nanoparticles in colloidal solutions and on supports were determined by TEM images and from XRD patterns. The size of Pt nanoparticles supported on SiO2 and CNT determined from XRD patterns is in a good agreement with size obtained from the TEM analyses. There were shown that no agglomeration and size changing of Pt nanoparticles on these supports were observed. All these findings illustrate that the method of colloid deposition allows one to obtain catalyst with monodisperse platinum nanoparticles of controlled size deposited on different supports without changing the nanoparticle’s size and morphology.
基金Project (50472098) supported by the National Natural Science Foundation of China
文摘BiFeO3 (BFO) thin films were prepared on Pt(111)/TiO2/SiO2/Si(100) substrates by the pulsed-laser deposition (PLD) technique at a low temperature of 450℃. The XRD results indicate that the BFO thin films are of perovskite structure with the presence of small amount of second phases. The oxygen pressures have great effect on the crystalline structures and dielectric properties of BFO thin films. The dielectric constant of the BFO thin films decreases with increasing oxygen pressures, achieving 186, 171 and 160 at the frequency of 104 Hz for the oxygen pressures of 0.666, 1.333 and 13.332 Pa, respectively. The BFO thin films prepared at the oxygen pressure of 0.666 Pa reveal a saturated hysteresis loop with the remanent polarization of 7.5 μC/cm2 and the coercive field of 176 kV/cm.
