Structural conversion using core-shell silver (Ag)-platinum (Pt) nanoparticles as starting materials is a promising way to produce nanocomposites consisting of silver sulfide (Ag 2 S) and hollow Pt nanostructures (Ag 2 S-hPtNCs). However, the mechanism behind the structural conversion process is yet to be understood. In this study, we use transmission electron microscope (TEM) as a typical tool to characterize the products formed in different structural conversion processes, and interpret the experimental observations by proposing mechanisms behind the reactions between core-shell Ag-Pt nanoparticles and sulfur precursors from different sources. We then design additional experiments to rationalize the formation mechanism we proposed. The mechanistic understanding of the structural conversion from bimetallic core-shell nanostructures to heterogeneous nanocomposites may extend the fabrication of heterogeneous nanocomposites for a given technological application.
In this paper, a facile bio-templating method is proposed to prepare NiCoP coated on amorphous carbon (NiCoP@AC) composite electrode materials with using bagasse as template and carbon source. NiCoP nanowire network arrays precursors coating on bagasse substrate with high yield were prepared via a novel synthesis strategy utilizing the toluene-water interface reaction process, which subsequently formed as NiCoP@AC composite electrode materials after phosphating process. The assembled core-shell structure attenuated the volume expansion during charging and discharging, additionally, the overall electrical conductivity of the composite was also improved owing to the characteristic of bagasse biochar. The NiCoP@AC electrode exhibited high specific capacitance (1706 F g −1 at 1 A g −1 ), outstanding rate capability (82.1 % capacity retention from 1 to 20 A g −1 ) and good cycling stability (retaining 80.0 % capacitance over 5000 cycles). In addition, bagasse biomass activated carbon (BAC) was prepared via a typical alkaline activation process for the use as negative electrode. The as-fabricated NiCoP@AC//BAC supercapacitor displayed a high energy density of 46.2 Wh kg −1 at a power density of 807.3 W kg −1 , and an excellent capacitance retention rate (88.5 % after 5000 cycles), suggesting that the as-prepared NiCoP@AC electrode materials have wide application prospects in high-performance supercapacitors.
Zhijia Zhang,Xiaole Zhao,Yingchun Su,Defeng Xing,Xiaojun Han
We demonstrate that antibacterial agent N , N′ -[(4, 5-dihydroxy-1, 2-phenylene)bis(methylene)]bisacrylamide (OHABA) can be assembled on the surface of vinyl organosilicon nanospheres (VOSNs) by atom transfer radical polymerization (ATRP). Chemically cross-linked vinyl organosilicon cores were facilely fabricated by sol-gel method as support, which densely grafted poly-OHABA (POHABA) as shells. Antibacterial assessment test results revealed that POHABA-based core@shell structure displayed high antibacterial performance, long-term stability, and kept broad-spectrum antibacterial effect of against Gram-negative and Gram-positive bacteria.