RESUMEN
A spray-pyrolysis process is introduced as an effective tool for the preparation of yolk-shell-structured materials with electrochemical properties suitable for anode materials in Li-ion batteries (LIBs). Yolk-shell-structured ZnO-Mn3O4 systems with various molar ratios of the Zn and Mn components are prepared. The yolk-shell-structured ZnO-Mn3O4 powders with a molar ratio of 1:1 of the Zn and Mn components are shown to have high capacities and good cycling performances.
RESUMEN
A facile, one-pot method of systematically synthesizing yolk-shell materials with complex compositions is proposed. The spray pyrolysis process for obtaining yolk-shell materials is advantageous because it is highly efficient, allows high throughput, comprises a single-step reaction, and is a continuous process that yields homogeneous composition and enables facile control of the mean size.
RESUMEN
Limited by the sluggish four-electron transfer process, designing high-performance nonprecious electrocatalysts for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is urgently desired for efficient rechargeable Zn-air batteries (ZABs). Herein, the successful synthesis of porous nitrogen-doped cobalt pyrite yolk-shell nanospheres (N-CoS2 YSSs) is reported. Benefiting from the abundant porosity of the porous yolk-shell structure and unique electronic properties by nitrogen doping, the as-prepared N-CoS2 YSSs possess more exposed active surface, thus giving rise to superior activity for reversible oxygen electrocatalysis and outstanding cycling stability (more than 165 h at 10 mA cm-2) in ZABs, exceeding the commercial Pt/C and RuO2 hybrid catalysts. Moreover, the assembled ZABs, delivering a specific capacity of 640 mAh gZn -1, can be used for practical devices. This work provides a novel tactic to engineer sulfides as high efficiency and promising bifunctional oxygen electrocatalysts for advanced metal-air batteries.
RESUMEN
In the present paper, we demonstrate a versatile approach for the one-pot synthesis of metal oxide yolk@shell nanostructures filled with bimetallic nanocores. This novel approach is based on the principles of hydrophobic nanoreactor soft-templating and is exemplified for the synthesis of various AgAuNP@tin-rich ITO (AgAu@ITOTR) yolk@shell nanomaterials. Hydrophobic nanoreactor soft-templating thereby takes advantage of polystyrene-block-poly(4-vinylpiridine) inverse micelles as two-compartment nanoreactor template, in which the core and the shell of the micelles serve as metal and metal oxide precursor reservoir, respectively. The composition, size and number of AuAg bimetallic nanoparticles incorporated within the ITOTR yolk@shell can easily be tuned. The conductivity of the ITOTR shell and the bimetallic composition of the AuAg nanoparticles, the as-synthesized AuAgNP@ITOTR yolk@shell materials could be used as efficient electrocatalysts for electrochemical glucose oxidation with improved onset potential when compared to their gold counterpart.