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1.
ACS Omega ; 6(39): 25720-25728, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34632228

RESUMO

In this work, we demonstrated a facile approach for fabrication of Au nanoflowers (Au NFs) using an amino-containing organosilane, 3-aminopropyltriethoxysilane (APTES), as a shape-directing agent. In this approach, the morphology of the Au particles evolved from sphere-like to flower-like with increasing the concentration of APTES, accompanied by a red shift in the localized surface plasmon resonance peak from 520 to 685 nm. It was identified that the addition of APTES is profitable to direct the preferential growth of the (111) plane of face-centered cubic gold and promote the formation of anisotropic Au NFs. The as-prepared Au NFs, with APTES on their surface, presented effective catalytic and surface-enhanced Raman scattering (SERS) performances, as evidenced by their applications in catalyzing the dimerization of p-aminothiophenol and monitoring the reaction process via in situ SERS analysis.

2.
ACS Appl Mater Interfaces ; 12(34): 38106-38112, 2020 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-32799447

RESUMO

Platinum-based single-atom catalysts (SACs) are among the most promising candidates for the practical applications of electrochemical hydrogen evolution reaction (HER), but their catalytic efficiency remains to be further enhanced. Herein, a well-designed nanoarray-structured nitrogen-doped graphite foil (NNGF) substrate is introduced to support Pt SACs in Pt-N4 construction (Pt1/NNGF) for HER. Within NNGF, the constructed nanoarray-structured surficial layer for supporting Pt SACs could enhance the exposure of active sites to the electrolyte and improve the reaction and diffusion kinetics; meanwhile, the retained graphite structures in bulk NNGF provide not only the required electrical conductivity but also the mechanical stability and flexibility. Because of such double-layer structures of NNGF, stable Pt-N4 construction, and binder-free advantages, the Pt1/NNGF electrode exhibits a low overpotential of 0.023 V at 10 mA cm-2 and a small Tafel slope of 29.1 mV dec-1 as well as an excellent long-term durability.

3.
ChemistryOpen ; 8(7): 1027-1032, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31367510

RESUMO

Developing cost-effective and highly efficient oxygen evolution reaction (OER) electrocatalysts is vital for the production of clean hydrogen by electrocatalytic water splitting. Here, three dimensional nickel-iron layered double hydroxide (NiFe LDH) nanosheet arrays are in-situ fabricated on self-supporting nitrogen doped graphited foam (NGF) via a one-step hydrothermal process under an optimized amount of urea. The as prepared NiFe LDH/NGF electrode exhibits a remarkable activity toward OER with a low onset overpotential of 233 mV and a Tafel slope of 59.4 mV dec-1 as well as a long-term durability. Such good performance is attributed to the synergy among the doping effect, the binder-free characteristic, and the architecture of the nanosheet array.

4.
J Hazard Mater ; 378: 120720, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31302477

RESUMO

For both fuel cycle design and safety evolution of tritium (T) in fusion reactor, it is important to study irradiation-induced reactions between T2 and various molecular species produced from nuclear-fusion fuel cleanup systems. The radiochemical reactions between deuterium-tritium/tritium and carbon monoxide of different concentrations under 1.0 MPa were elucidated in this work. The products and the process of radiochemical reactions of T2/CO and D2-T2/CO mixed system with different tritium concentrations were analyzed by mass spectrometry and gas chromatography. The evolution of the product composition in 300 min. was monitored at room temperature with a rapid decrease of tritium concentration and pressure. It was found that, in T2/CO and D2-T2/CO mixed system, only tritium was involved in the reaction of CO. Under the ß irradiation of tritium, the reaction products were mainly composed of tritiated formaldehyde (CT2O) and tiny amount of CO2, C(DT)4, C3(DT)8. The concentration of products rose with the increase of CO concentration in reaction system.

5.
Scanning ; 2018: 5736742, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29721128

RESUMO

The effects of ball milling on the hydrogen sorption kinetics and microstructure of Zr0.8Ti0.2Co have been systematically studied. Kinetic measurements show that the hydrogenation rate and amount of Zr0.8Ti0.2Co decrease with increasing the ball milling time. However, the dehydrogenation rate accelerates as the ball milling time increases. Meanwhile, the disproportionation of Zr0.8Ti0.2Co speeds up after ball milling and the disproportionation kinetics is clearly inclined to be linear with time at 500°C. It is found from X-ray powder diffraction (XRD) results that the lattice parameter of Zr0.8Ti0.2Co gradually decreases from 3.164 Å to 3.153 Å when the ball milling time extends from 0 h to 8 h, which is mainly responsible for the hydrogen absorption/desorption behaviors. In addition, scanning electron microscope (SEM) images demonstrate that the morphology of Zr0.8Ti0.2Co has obviously changed after ball milling, which is closely related to the hydrogen absorption kinetics. Besides, high-resolution transmission electron microscopy (HRTEM) images show that a large number of disordered microstructures including amorphous regions and defects exist after ball milling, which also play an important role in hydrogen sorption performances. This work will provide some insights into the principles of how to further improve the hydrogen sorption kinetics and disproportionation property of Zr0.8Ti0.2Co.

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