We present the design and synthesis of three-dimensional (3D)-networked NiCo 2 S 4 nanosheet arrays (NSAs) grown on carbon cloth along with their novel application as anodes in lithium-ion batteries. The relatively small (~60%) volumetric expansion of NiCo 2 S 4 nanosheets during the lithiation process was confirmed by in situ transmission electron microscopy and is attributed to their mesoporous nature. The 3D network structure of NiCo 2 S 4 nanosheets offers the additional advantages of large surface area, efficient electron and ion transport capability, easy access of electrolyte to the electrode surface, sufficient void space and mechanical robustness. The fabricated electrodes exhibited outstanding lithium-storage performance including high specific capacity, excellent cycling stability and high rate of performance. A reversible capacity of~1275 mAh g − 1 was obtained at a current density of 1000 mA g − 1 , and the devices retained~1137 mAh g − 1 after 100 cycles, which is the highest value reported to date for electrodes made of metal sulfide nanostructures or their composites. Our results suggest that 3D-networked NiCo 2 S 4 NSA/carbon cloth composites are a promising material for electrodes in high-performance lithium-ion batteries. INTRODUCTIONRechargeable lithium-ion batteries (LIBs) are the most widely used electrochemical energy storage devices because of their inherent advantages including high energy density, long life span, lack of memory effect and environmental nontoxicity. 1-3 The increasing applications of LIBs in daily electronic devices-along with industry demands for further improvement in energy density, durability, rate capability and safety-have driven the development of new electrode materials and new electrode structures. [4][5][6][7] Among the great variety of anode materials studied, metal oxides (MOs) and metal sulfides ( 21 have been synthesized and offer superior electrochemical energy storage capacity compared with bulk MSs. However, the large volumetric change of MS nanostructures during electrochemical reactions leads to reduced capacity and poor cycling stability. Moreover, the necessary addition of conductive additives and binders inevitably lessens overall energy

A composite of pyrite FeS2 microspheres wrapped by reduced graphene oxide (FeS2/rGO) has been synthesized by a facile one-step solvothermal method and applied as an anode in lithium ion batteries (LIBs).

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Surface-enhanced Raman spectroscopy (SERS) substrates based on plasmonic nanostructures allow for label-free and fingerprinting molecular detection with ultrahigh sensitivity and selectivity, but their complicated and high-cost fabrication remains a challenge for practical applications and commercialization of SERS technology. Herein, we developed a facile and low-cost natural SERS substrate based on silver coated taro leaf (Taro-leaf@Ag) that exhibits ordered micro-papillae and secondary crossed nanoplates. The micro-papillae exhibited superior superhydrophobicity for analyte enrichment and the secondary crossed nanoplates provided rich SERS hot spots, which together lead to highly sensitive SERS detection with a detection limit as low as 10(-8) M. Moreover, the crossed nanoplates were uniformly distributed such that reproducible SERS measurements with a 9.7% variation over 1274 spectra was achieved. The high SERS sensitivity and reproducibility as well as the facile and low-cost fabrication make the Taro-leaf@Ag a promising natural SERS substrate for future practical biochemical detection methods.

A simple and efficient ultrasound-assisted wet chemical-synthesized rGO/cobalt sulfide anode exhibits high lithium storage capacity and excellent rate capability.