In situ template synthesis of hollow nanospheres assembled from NiCo2S4@C ultrathin nanosheets with high electrochemical activities for lithium storage and ORR catalysis. Issue 18 (20th April 2017)

• Record Type: Journal Article
• Authors: Wu, Xiaoyu; Li, Songmei; Wang, Bo; Liu, Jianhua; Yu, Mei
• Is Part Of: Physical chemistry chemical physics. Volume 19:Issue 18(2017)
• Page Start: 11554
• Page End: 11562
• Publication Date: 2017-04-20
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c7cp00509a
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : NiCo2 S4 @C ultrathin nanosheet assembled hollow nanospheres are fabricated by synchronized sulfurization and in situ template removal, and exhibit high electrochemical activities for lithium storage and ORR catalysis. Abstract : Transition-metal sulfide hollow nanostructures have received intensive attention in energy-related applications due to their unique structural features and high electrochemical activities. Here, a well-designed composite of NiCo2 S4 @C is successfully fabricated using a facile in situ template removal method. The obtained composite shows unique microstructures of hollow nanospheres (∼650 nm in diameter) assembled from ultrathin NiCo2 S4 @C nanosheets, in which numerous scattered NiCo2 S4 nanoparticles are embedded in ultrathin carbon nanosheets, exhibiting mesoporous features with a high surface area of 247.25 m 2 g −1 . When used as anode materials for LIBs, NiCo2 S4 @C hollow nanospheres exhibit a high reversible capacity of 1592 mA h g −1 at a current density of 500 mA g −1, enhanced cycling performance maintaining a capacity of 1178 mA h g −1 after 200 cycles, and a remarkable rate capability. Meanwhile, the hollow nanospheres display excellent catalytic activity as ORR catalysts with a four-electron pathway and superior durability to that of commercial Pt/C catalysts. Their excellent lithium storage and ORR catalysis performance can be attributed to the rational incorporation of high-activity NiCo2 S4 and ultrathin carbon nanosheets, as well as unique hollow microstructures, which offer efficient electron/ion transport, an enhanced electroactive material/electrolyte contact area, numerous active sites, and excellent structural stability.