Microwave-assisted synthesis of gold and silver nanoparticles, as a function of Green Chemistry, non Green Chemistry, and four applicator types are reported. The applicator types are Domestic microwave ovens, commerci...Microwave-assisted synthesis of gold and silver nanoparticles, as a function of Green Chemistry, non Green Chemistry, and four applicator types are reported. The applicator types are Domestic microwave ovens, commercial temperature controlled microwave chemistry ovens (TCMC), digesters, and axial field helical antennae. For each of these microwave applicators the process energy budget where estimated (Watts multiplied by process time = kJ) and energy density (applied energy divided by suspension volume = kJ·ml<sup>-1</sup>) range between 180 ± 176.8 kJ, and 79.5 ± 79 kJ·ml<sup>-1</sup>, respectively. The axial field helical field an-tenna applicator is found to be the most energy efficient (0.253 kJ·m<sup>-1</sup> per kJ, at 36 W). Followed by microwave ovens (4.47 ± 3.9 kJ·ml<sup>-1</sup> per 76.83 ± 39 kJ), and TCMC ovens (2.86 ± 2.3 kJ·m<sup>-1</sup> per 343 ± 321.5 kJ). The digester applicators have the least energy efficiency (36.2 ± 50.7 kJ·m<sup>-1</sup> per 1010 ± 620 kJ). A comparison with reconstructed ‘non-thermal’ microwave oven inactivation microorganism experiments yields a power-law signature of n = 0.846 (R<sup>2</sup> = 0.7923) four orders of magnitude. The paper provides a discussion on the Au and Ag nanoparticle chemistry and bio-chemistry synthesis aspects of the microwave applicator energy datasets and variation within each dataset. The visual and analytical approach within the energy phase-space projection enables a nanoparticle synthesis route to be systematically characterized, and where changes to the synthesis are to be mapped and compared directly with historical datasets. In order to help identify lower cost nanoparticle synthesis, in addition to potentially reduce synthesis energy to routes informed changes to potentially reduce synthesis energy budget, along with nanoparticle morphology and yield.展开更多
Triangular Au-Ag framework nanostructures （TFN） were synthesized via a multi-step galvanic replacement reaction （MGRR） of single-crystalline triangular silver nanoplates in a chlorauric acid （HAuCl4） solution at...Triangular Au-Ag framework nanostructures （TFN） were synthesized via a multi-step galvanic replacement reaction （MGRR） of single-crystalline triangular silver nanoplates in a chlorauric acid （HAuCl4） solution at room temperature. The morphological, compositional, and crystal structural changes involved with reaction steps were analyzed by using transmission electron microscopy（TEM）, energy-dispersive X-ray spectrometry （EDX）, and X-ray diffraction. TEM combined with EDX and selected area electron diffraction confirmed the replacement of Ag with Au. The in-plane dipolar surface plasmon resonance （SPR） absorption band of the Ag nanoplates locating initially at around 700 nm gradually redshifted to 1 100 nm via a multi-stage replacement manner after 7 stages. The adding amount of HAuCl4 per stage influenced the average redshift value per stage, thus enabled a fine tuning of the in-plane dipolar band. A proposed formation mechanism of the original Ag nanoplates developing pores while growing Au nanoparticles covering this underlying structure at more reaction steps was confirmed by exploiting surface-enhanced Raman scattering （SERS）.展开更多
TiO2 nanotubes were prepared under normal pressure at a temperature of 120 ℃. Ag, Au, Pt nanoparticles supported on TiO2 nanotubes were prepared by m icrowave assisted heating polyol process. TEM images showed that m...TiO2 nanotubes were prepared under normal pressure at a temperature of 120 ℃. Ag, Au, Pt nanoparticles supported on TiO2 nanotubes were prepared by m icrowave assisted heating polyol process. TEM images showed that microwave prepa red Ag, Au, Pt nanoparticles supported on TiO2 nanotubes were small and well dis persed on the surface of the TiO2 nanotubes. UV-Vis absorption spectra showed th at the absorbance of Ag/TiO2 nanotubes and Au/TiO2 nanotubes in the visible ligh t range increased greatly compared to the single titania nanotubes.展开更多
文摘Microwave-assisted synthesis of gold and silver nanoparticles, as a function of Green Chemistry, non Green Chemistry, and four applicator types are reported. The applicator types are Domestic microwave ovens, commercial temperature controlled microwave chemistry ovens (TCMC), digesters, and axial field helical antennae. For each of these microwave applicators the process energy budget where estimated (Watts multiplied by process time = kJ) and energy density (applied energy divided by suspension volume = kJ·ml<sup>-1</sup>) range between 180 ± 176.8 kJ, and 79.5 ± 79 kJ·ml<sup>-1</sup>, respectively. The axial field helical field an-tenna applicator is found to be the most energy efficient (0.253 kJ·m<sup>-1</sup> per kJ, at 36 W). Followed by microwave ovens (4.47 ± 3.9 kJ·ml<sup>-1</sup> per 76.83 ± 39 kJ), and TCMC ovens (2.86 ± 2.3 kJ·m<sup>-1</sup> per 343 ± 321.5 kJ). The digester applicators have the least energy efficiency (36.2 ± 50.7 kJ·m<sup>-1</sup> per 1010 ± 620 kJ). A comparison with reconstructed ‘non-thermal’ microwave oven inactivation microorganism experiments yields a power-law signature of n = 0.846 (R<sup>2</sup> = 0.7923) four orders of magnitude. The paper provides a discussion on the Au and Ag nanoparticle chemistry and bio-chemistry synthesis aspects of the microwave applicator energy datasets and variation within each dataset. The visual and analytical approach within the energy phase-space projection enables a nanoparticle synthesis route to be systematically characterized, and where changes to the synthesis are to be mapped and compared directly with historical datasets. In order to help identify lower cost nanoparticle synthesis, in addition to potentially reduce synthesis energy to routes informed changes to potentially reduce synthesis energy budget, along with nanoparticle morphology and yield.
基金Project(10804101)supported by the National Natural Science Foundation of ChinaProject(2007CB815102)supported by the National Basic Research Program of ChinaProject(2007B08007)supported by the Science and Technology Development Foundation of Chinese Academy of Engineering Physics,China
文摘Triangular Au-Ag framework nanostructures （TFN） were synthesized via a multi-step galvanic replacement reaction （MGRR） of single-crystalline triangular silver nanoplates in a chlorauric acid （HAuCl4） solution at room temperature. The morphological, compositional, and crystal structural changes involved with reaction steps were analyzed by using transmission electron microscopy（TEM）, energy-dispersive X-ray spectrometry （EDX）, and X-ray diffraction. TEM combined with EDX and selected area electron diffraction confirmed the replacement of Ag with Au. The in-plane dipolar surface plasmon resonance （SPR） absorption band of the Ag nanoplates locating initially at around 700 nm gradually redshifted to 1 100 nm via a multi-stage replacement manner after 7 stages. The adding amount of HAuCl4 per stage influenced the average redshift value per stage, thus enabled a fine tuning of the in-plane dipolar band. A proposed formation mechanism of the original Ag nanoplates developing pores while growing Au nanoparticles covering this underlying structure at more reaction steps was confirmed by exploiting surface-enhanced Raman scattering （SERS）.
文摘TiO2 nanotubes were prepared under normal pressure at a temperature of 120 ℃. Ag, Au, Pt nanoparticles supported on TiO2 nanotubes were prepared by m icrowave assisted heating polyol process. TEM images showed that microwave prepa red Ag, Au, Pt nanoparticles supported on TiO2 nanotubes were small and well dis persed on the surface of the TiO2 nanotubes. UV-Vis absorption spectra showed th at the absorbance of Ag/TiO2 nanotubes and Au/TiO2 nanotubes in the visible ligh t range increased greatly compared to the single titania nanotubes.
