Liangbiao Wang

Anion exchange strategy to synthesis of porous NiS hexagonal nanoplates for supercapacitors

A facile anion exchange strategy was applied to the synthesis of porous NiS hexagonal nanoplates (NiS HNPs) as an electrode material for supercapacitors. It was found that Na2S concentration is a key factor to achieve porous NiS hexagonal nanoplates with well-defined architecture. Porous NiS hexagonal nanoplates exhibited a specific capacitance of 1897 F g-1 at a current density of 1 A g-1. NiS HNPs//activated carbon (AC) asymmetric supercapacitor (ASC) shows a long cycle lifespan (about 100% capacity retention after 4000 cycles at a current density of 3 A g-1) with a maximum energy density of 11.6 Wh kg-1 at a large loading mass of about 30 mg. Impressively, two NiS HNPs//AC ASCs in series could light up a red LED for about 30 min. The remarkable electrochemical performance of NiS HNPs is ascribed to their unique hierarchical porous architectures. The anion exchange method is a facile and versatile strategy for the synthesis of metal sulfides with high performance for energy storage.

Sulfur-assisted synthesis of indium nitride nanoplates from indium oxide

Indium nitride (InN) is much more difficult to prepare than other group III nitrides for its low thermal stability. Here, InN nanoplates are prepared by using In2O3, NaNH2 and sulfur as starting materials in a stainless steel autoclave at 190 °C. This method has the advantages of requiring a low temperature and without using an ammonia flow. Field-emission scanning electron microscope shows that the length of InN nanoplates is about 400 nm with the thickness of 50 nm. Finally, the formation mechanism is also investigated.

One-step solid state reaction for the synthesis of ternary nitrides Co3Mo3N and Fe3Mo3N

Intermetallic ternary Mo-nitrides are important functional materials due to their unique physical and chemical properties. However, the preparation of this class of materials is usually divided into two steps: the first step is the preparation of the ternary oxides, the second step is the nitridation of the ternary oxides. In this study, a facile procedure for synthesizing ternary Mo-nitrides has been reported. Co3Mo3N and Fe3Mo3N nanoparticles have been synthesized by a one step solid state reaction in a sealed autoclave at 750 °C. The structures and morphologies of the obtained products are derived from X-ray diffraction and electron microscopy. Furthermore, the oxidation resistances and magnetic properties of the obtained products have been investigated.

A novel class of functional additives for cyclability enhancement of the sulfur cathode in lithium sulfur batteries

A novel class of functional additives for lithium sulfur batteries was studied. In particular, the facile operation of adding LiCoO2 (LCO) to the sulfur cathode achieves a remarkably improved cycling performance i.e. an ultralow capacity degradation of 0.034% per cycle at a 2C rate over 1200 cycles with a LCO addition of only 3 wt%.

Solid-state synthesis and magnetic properties of rhombohedral phase Mg2SiNi3

Abstract A solid-state route was developed to prepare rhombohedral phase Mg2SiNi3 with the dimensions of about 300 nm by using metallic magnesium, nickel oxide and silicon as starting materials at 700 °C in an autoclave reactor. The obtained product was investigated by means of X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Magnetic measurement at room temperature indicated that the values of saturation magenetization and coercivity of the obtained Mg2SiNi3 were 0.31 emu g–1 and 65.20 Oe, respectively.

Low-Temperature Solid State Synthesis and Characterization of Superconducting Vanadium Nitride*

Superconducting vanadium nitride (VN) is successfully synthesized by a solid-state reaction of vanadium pentoxide, sodium amide and sulfur in an autoclave at a relatively low temperature (240–400°C). The obtained samples are characterized by x-ray diffraction, x-ray photoelectron spectroscopy and transmission electron microscopy. The result of the magnetization of the obtained VN product as a function of temperature indicates that the onset superconducting transition temperature is about 8.4 K. Furthermore, the possible reaction mechanism is also discussed.