The Ni-coated carbon nanotubes(Ni@CNT)composite was synthesized by the facile“filtration+calcination”of Ni-based metal−organic framework(MOF)precursor and the obtained composite was used as a catalyst for MgH_(2).Mg...The Ni-coated carbon nanotubes(Ni@CNT)composite was synthesized by the facile“filtration+calcination”of Ni-based metal−organic framework(MOF)precursor and the obtained composite was used as a catalyst for MgH_(2).MgH_(2)was mixed evenly with different amounts of Ni@CNT(2.5,5.0 and 7.5,wt.%)through ball milling.The MgH_(2)−5wt.%Ni@CNT can absorb 5.2 wt.%H_(2)at 423 K in 200 s and release about 3.75 wt.%H_(2)at 573 K in 1000 s.And its dehydrogenation and rehydrogenation activation energies are reduced to 87.63 and 45.28 kJ/mol(H_(2)).The in-situ generated Mg_(2)Ni/Mg_(2)NiH4 exhibits a good catalytic effect due to the provided more diffusion channels that can be used as“hydrogen pump”.And the presence of carbon nanotubes improves the properties of MgH_(2)to some extent.展开更多
A series of Au/[NiCo/Bi]x/Au （x = 2, 3） films were fabricated by pulsed laser deposition method. In order to induce the in-plane uniaxial magnetic anisotropy （IPUMA） of the multifilms, multiple layers and differen...A series of Au/[NiCo/Bi]x/Au （x = 2, 3） films were fabricated by pulsed laser deposition method. In order to induce the in-plane uniaxial magnetic anisotropy （IPUMA） of the multifilms, multiple layers and different oblique angles ranging from 0° to 30° for the substrate are applied during the deposition. The microstructures of the nanofilms were investigated by using X-ray diffraction （XRD） and transmission electronic microscope （TEM）. And their magnetic properties were measured by an alternating gradient magnetometer. For the multicycle systems, using the method that with more periodic structures of NiCo/Bi film is easier for inducing IPUMA than the less or the samples located with various angles.展开更多
Cobalt and cobalt oxide nanocrystals were synthesized on Si substrates from aqueous cobalt nitrate [Co（NO3）2·6H2O] powder via chemical vapor deposition method. Scanning electron microscope, field emission scann...Cobalt and cobalt oxide nanocrystals were synthesized on Si substrates from aqueous cobalt nitrate [Co（NO3）2·6H2O] powder via chemical vapor deposition method. Scanning electron microscope, field emission scanning electron microscope, and transmission electron microscope observations show different morphologies, such as continuous films, nano-bars, nano-dices, and nano-strings, depending on the synthesis temperature. The crystal structure characterization was conducted using X- ray diffraction methods. Furthermore, the properties of the samples were characterized using Raman spectroscopic analysis and vibrating sample magnetometer. The morphology change was discussed in terms of synthesis environments and chemical interactions between cobalt, oxygen, and silicon.展开更多
基金the National Natural Science Foundation of China(Nos.52101274,51731002)Natural Science Foundation of Shandong Province,China(Nos.ZR2020QE011,ZR2022ME089)+1 种基金Youth Top Talent Foundation of Yantai University,China(No.2219008)Graduate Innovation Foundation of Yantai University,China(No.GIFYTU2240).
文摘The Ni-coated carbon nanotubes(Ni@CNT)composite was synthesized by the facile“filtration+calcination”of Ni-based metal−organic framework(MOF)precursor and the obtained composite was used as a catalyst for MgH_(2).MgH_(2)was mixed evenly with different amounts of Ni@CNT(2.5,5.0 and 7.5,wt.%)through ball milling.The MgH_(2)−5wt.%Ni@CNT can absorb 5.2 wt.%H_(2)at 423 K in 200 s and release about 3.75 wt.%H_(2)at 573 K in 1000 s.And its dehydrogenation and rehydrogenation activation energies are reduced to 87.63 and 45.28 kJ/mol(H_(2)).The in-situ generated Mg_(2)Ni/Mg_(2)NiH4 exhibits a good catalytic effect due to the provided more diffusion channels that can be used as“hydrogen pump”.And the presence of carbon nanotubes improves the properties of MgH_(2)to some extent.
基金financially supported by the National Basic Research Program of China(No.2010CB934602)the National Natural Science Foundation of China(No.51171007 and No.51271009)the Special Funding for Major Scientific Research Instrument and Equipment of NSFC(No.61227902)
文摘A series of Au/[NiCo/Bi]x/Au （x = 2, 3） films were fabricated by pulsed laser deposition method. In order to induce the in-plane uniaxial magnetic anisotropy （IPUMA） of the multifilms, multiple layers and different oblique angles ranging from 0° to 30° for the substrate are applied during the deposition. The microstructures of the nanofilms were investigated by using X-ray diffraction （XRD） and transmission electronic microscope （TEM）. And their magnetic properties were measured by an alternating gradient magnetometer. For the multicycle systems, using the method that with more periodic structures of NiCo/Bi film is easier for inducing IPUMA than the less or the samples located with various angles.
文摘Cobalt and cobalt oxide nanocrystals were synthesized on Si substrates from aqueous cobalt nitrate [Co（NO3）2·6H2O] powder via chemical vapor deposition method. Scanning electron microscope, field emission scanning electron microscope, and transmission electron microscope observations show different morphologies, such as continuous films, nano-bars, nano-dices, and nano-strings, depending on the synthesis temperature. The crystal structure characterization was conducted using X- ray diffraction methods. Furthermore, the properties of the samples were characterized using Raman spectroscopic analysis and vibrating sample magnetometer. The morphology change was discussed in terms of synthesis environments and chemical interactions between cobalt, oxygen, and silicon.
