Pd-Ag bimetallic alloy nanoparticles were synthesized by the reverse microemulsion method, and then deposited on A1203 to form the supported catalyst. The nanoparticles of Pd-Ag and Pd-Ag/AI203 samples were characteri...Pd-Ag bimetallic alloy nanoparticles were synthesized by the reverse microemulsion method, and then deposited on A1203 to form the supported catalyst. The nanoparticles of Pd-Ag and Pd-Ag/AI203 samples were characterized by UV/ Vis, HRTEM, EDX, XRD, and XPS. The test results indicated that Pd-Ag bimetallic alloy nanoparticles with a size of about 2 nm and a face-centered cubic （fcc） structure were formed in the measured area of microemulsion. The growth of nanopar- ticles was effectively limited within the droplet of micoremulsion. TEM image exhibited that the Pd-Ag alloy nanoparticles were well-dispersed on the A1203 support. The catalytic performance of various catalysts for selective hydrogenation of acetylene showed that a higher acetylene conversion and selectivity to ethylene upon acetylene hydrogenation was achieved on a nano-sized Pd-Ag bimetallic catalyst with a Pd/Ag alloy supported molar ratio of 1：1.5.展开更多
A nano-crystal N–Zn/TiO 2 anode film was prepared using a combined technology. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and cyclic voltammetry characterizations showed tha...A nano-crystal N–Zn/TiO 2 anode film was prepared using a combined technology. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and cyclic voltammetry characterizations showed that the two elements N and Zn were doped into nano-crystal TiO 2 successfully. This resulted in a strong redshift in the UV-Visible spectrum. UV-Visible measurements showed that the light absorption of N719 and P3OT were complementary and covered the entire visible region. This led to a high utilization of visible light. Solar cells based on the N–Zn/TiO 2 anode film were co-sensitized using P3OT and N719. The cells have a short-circuit current density of 7.91 mA/cm 2 , an open-circuit photovoltage of 0.659 V, and a photoelectric conversion efficiency of 2.64%. Also, the relationship among the N–Zn/TiO 2 -film anode’s electric structure, the dye’s LUMO, electrochemical impedance, and photoelectric conversion efficiency are discussed in the paper.展开更多
Silver behenate nanocrystals were first prepared by chemical precipitation in a water tert-butyl alcohol mixed solvent. The influence of main factors on the silver behenate crystal size was studied. The morphology, cr...Silver behenate nanocrystals were first prepared by chemical precipitation in a water tert-butyl alcohol mixed solvent. The influence of main factors on the silver behenate crystal size was studied. The morphology, crystal structure and ther- mal behavior of silver behenate nanocrystals were investigated using SEM, TEM, XRD, IR and TG-DTA. These results showed that the preparation method, reaction temperature and excessive silver ion con- centration in reaction solution played important roles in determining the size of silver behenate nanocrys- tals. The prepared silver behenates were scaly crys- tals with a mean diameter of about 70 nm. The silver behenate nanocrystals possessed layer structure. A series of structural changes of silver behenate nanocrystals were observed at different temperatures. The silver behenate nanocrystals had excellent thermal stability below 120℃. At high temperature there were two distinct transitions resulting in dra- matic structural changes. In the first transition at 138℃, the alkyl chains of silver behenate were trans- formed from an ordered into a disordered state. In the second transition at 230℃, a completely irreversible structural change took place due to the decomposi- tion of silver behenate nanocrystals.展开更多
文摘Pd-Ag bimetallic alloy nanoparticles were synthesized by the reverse microemulsion method, and then deposited on A1203 to form the supported catalyst. The nanoparticles of Pd-Ag and Pd-Ag/AI203 samples were characterized by UV/ Vis, HRTEM, EDX, XRD, and XPS. The test results indicated that Pd-Ag bimetallic alloy nanoparticles with a size of about 2 nm and a face-centered cubic （fcc） structure were formed in the measured area of microemulsion. The growth of nanopar- ticles was effectively limited within the droplet of micoremulsion. TEM image exhibited that the Pd-Ag alloy nanoparticles were well-dispersed on the A1203 support. The catalytic performance of various catalysts for selective hydrogenation of acetylene showed that a higher acetylene conversion and selectivity to ethylene upon acetylene hydrogenation was achieved on a nano-sized Pd-Ag bimetallic catalyst with a Pd/Ag alloy supported molar ratio of 1：1.5.
基金supported by the National High Technology Research and Development Program of China (2006AA03z412)the Department of Education Research Project of Hainan (Hj2010-52)+2 种基金the Scientific Research Foundation of the Graduate School of Beijing University of Chemical and Technology (09Si005)the Key Science Planning Program of Hainan (ZDXM20100062)the National High Technology Research and Development Program of Hainan (509013)
文摘A nano-crystal N–Zn/TiO 2 anode film was prepared using a combined technology. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and cyclic voltammetry characterizations showed that the two elements N and Zn were doped into nano-crystal TiO 2 successfully. This resulted in a strong redshift in the UV-Visible spectrum. UV-Visible measurements showed that the light absorption of N719 and P3OT were complementary and covered the entire visible region. This led to a high utilization of visible light. Solar cells based on the N–Zn/TiO 2 anode film were co-sensitized using P3OT and N719. The cells have a short-circuit current density of 7.91 mA/cm 2 , an open-circuit photovoltage of 0.659 V, and a photoelectric conversion efficiency of 2.64%. Also, the relationship among the N–Zn/TiO 2 -film anode’s electric structure, the dye’s LUMO, electrochemical impedance, and photoelectric conversion efficiency are discussed in the paper.
文摘Silver behenate nanocrystals were first prepared by chemical precipitation in a water tert-butyl alcohol mixed solvent. The influence of main factors on the silver behenate crystal size was studied. The morphology, crystal structure and ther- mal behavior of silver behenate nanocrystals were investigated using SEM, TEM, XRD, IR and TG-DTA. These results showed that the preparation method, reaction temperature and excessive silver ion con- centration in reaction solution played important roles in determining the size of silver behenate nanocrys- tals. The prepared silver behenates were scaly crys- tals with a mean diameter of about 70 nm. The silver behenate nanocrystals possessed layer structure. A series of structural changes of silver behenate nanocrystals were observed at different temperatures. The silver behenate nanocrystals had excellent thermal stability below 120℃. At high temperature there were two distinct transitions resulting in dra- matic structural changes. In the first transition at 138℃, the alkyl chains of silver behenate were trans- formed from an ordered into a disordered state. In the second transition at 230℃, a completely irreversible structural change took place due to the decomposi- tion of silver behenate nanocrystals.
