Fabrication of VO 2

VO2 (B) nanobelts have been successfully synthesized via a simple hydrothermal route. The products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and Raman spectrum. These nanobelts are of rectangular cross-section with mean length about 1 μm, mean width about 80 nm, and mean thickness about 50 nm. The as-synthesized VO2 nanobelts were assembled as the cathode electrodes of lithium ion batteries. Their electrochemical properties were studied by conventional charge/discharge tests, which show an initial discharge capacity of 321 mAh g−1 with voltage plateau near 2.5 V. These results indicated that such hydrothermally synthesized VO2 (B) nanobelts could be an ideal candidate of cathode material for lithium ion battery

W18O49 Nanowires as Ultraviolet Photodetector

Photodetectors in a configuration of field effect transistor were fabricated based on individual W18O49 nanowires. Evaluation of electrical transport behavior indicates that the W18O49 nanowires are n-type semiconductors. The photodetectors show high sensitivity, stability and reversibility to ultraviolet (UV) light. A high photoconductive gain of 104 was obtained, and the photoconductivity is up to 60 nS upon exposure to 312 nm UV light with an intensity of 1.6 mW/cm2. Absorption of oxygen on the surface of W18O49 nanowires has a significant influence on the dark conductivity, and the ambient gas can remarkably change the conductivity of W18O49 nanowire. The results imply that W18O49 nanowires will be promising candidates for fabricating UV photodetectors

Self-adaptive electrochemical reconstruction boosted exceptional Li+ ion storage in a Cu3P@C anode

Self-adaptive electrochemical reconstruction is proven to trigger superior performance of conversion anode materials for Li-ion batteries. In the case of Cu3P, Cu3P dots embedded in a carbon matrix resulting in high Li-ion storage activity, improved electronic conductivity and stability is induced and results in an ultralong (>10000 cycles) lifespan.MOE (Min. of Education, S’pore

C‑Doped LiVO₃ Honeycombs Derived from the Biomass Template Strategy for Superior Lithium Storage

LiVO3 as a prospective anode for lithium-ion batteries has drawn considerable focus based on its superior ion transfer capability and relatively elevated specific capacity. Nevertheless, the inherent low electrical conductivity and sluggish reaction kinetics hindered its commercial application. Herein, C-doped LiVO3 honeycombs (C-doped LiVO3 HCs) are designed via introducing low-cost and scalable biomass carbon as a template, and the influence of the structure on the lithium storage property is systematically studied. The prepared C-doped LiVO3 HC electrode delivers a high reversible capacity of 743.7 mA h g–1 at 0.5 A g–1 after 400 cycles and superior high-rate performance with an average discharge capacity of 420.8 mA h g–1 even at 5.0 A g–1. The remarkable comprehensive electrochemical performance is attributed to the high electrical conductivity caused by carbon doping and rapid ion transport triggered by the honeycomb structure. This work may offer a rational design on both the hierarchical structure and doping engineering of future battery electrodes

Superior Li-ion storage of VS4 nanowires anchored on reduced graphene

Research on VS4 is lagging due to the difficulty in its tailored synthesis. Herein, unique architecture design of one-dimensional VS4 nanowires anchored on reduced graphene oxide is demonstrated via a facile solvothermal synthesis. Different amounts of reduced graphene oxide with VS4 are synthesized and compared regarding their rate capability and cycling stability. Among them, VS4 nanowires@15 wt% reduced graphene oxide present the best electrochemical performance. The superior performance is attributed to the optimal amount of reduced graphene oxide and one-dimensional VS4 nanowires based on (i) the large surface area that could accommodate volume changes, (ii) enhanced accessibility of the electrolyte, and (iii) improvement in electrical conductivity. In addition, kinetic parameters derived from electrochemical impedance spectroscopy spectra and sweep rate dependent cyclic voltammetry curves such as charge transfer resistances and Li+ ion apparent diffusion coefficients both support this claim. The diffusion coefficient is calculated to be 1.694 × 10-12 cm2 s-1 for VS4 nanowires/15 wt% reduced graphene oxide, highest among all samples.Ministry of Education (MOE)This research was supported by Tier 1 (AcRF grant MOE Singapore M4011528), Tier 2 (AcRF grant MOE Singapore M4020159), Tier 2 (MOE2015-T2-1-148), Chinese Natural Science Foundation (Grant No. 51271031), and Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 51802091)