Wuhan University of Technology

About: Wuhan University of Technology is a education organization based out in Wuhan, China. It is known for research contribution in the topics: Microstructure & Catalysis. The organization has 40384 authors who have published 36724 publications receiving 575695 citations. The organization is also known as: WUT.

Mesoporous NiS2 Nanospheres Anode with Pseudocapacitance for High-Rate and Long-Life Sodium-Ion Battery.

Abstract: It is of great importance to exploit electrode materials for sodium-ion batteries (SIBs) with low cost, long life, and high-rate capability. However, achieving quick charge and high power density is still a major challenge for most SIBs electrodes because of the sluggish sodiation kinetics. Herein, uniform and mesoporous NiS2 nanospheres are synthesized via a facile one-step polyvinylpyrrolidone assisted method. By controlling the voltage window, the mesoporous NiS2 nanospheres present excellent electrochemical performance in SIBs. It delivers a high reversible specific capacity of 692 mA h g−1. The NiS2 anode also exhibits excellent high-rate capability (253 mA h g−1 at 5 A g−1) and long-term cycling performance (319 mA h g−1 capacity remained even after 1000 cycles at 0.5 A g−1). A dominant pseudocapacitance contribution is identified and verified by kinetics analysis. In addition, the amorphization and conversion reactions during the electrochemical process of the mesoporous NiS2 nanospheres is also investigated by in situ X-ray diffraction. The impressive electrochemical performance reveals that the NiS2 offers great potential toward the development of next generation large scale energy storage.

General Strategy for the Synthesis of Transition-Metal Phosphide/N-Doped Carbon Frameworks for Hydrogen and Oxygen Evolution.

Abstract: Transition metal phosphides (TMPs) have been identified as promising nonprecious metal electrocatalyst for hydrogen evolution reaction (HER) and other energy conversion reactions. Herein, we reported a general strategy for synthesis of a series of TMPs (Fe2P, FeP, Co2P, CoP, Ni2P, and Ni12P5) nanoparticles (NPs) with different metal phases embedded in a N-doped carbon (NC) matrix using metal salt, ammonium dihydrogen phosphate, and melamine as precursor with varying molar ratios and thermolysis temperatures. The resultant TMPs can serve as highly active and durable bifunctional electrocatalyst toward HER and oxygen evolution reaction (OER). In particular, the Ni2P@NC phase only requires an overpotential of ∼138 mV to derive HER in 0.5 M H2SO4, and ∼320 mV for OER in 1.0 M KOH at the current density of 10 mA cm–2. Because of the encapsulation of NC that can effectively prevent corrosion of embedded TMP NPs, Ni2P@NC exhibits almost unfading catalytic performance even after 10 h under both acidic and alkalin...

Hierarchical NiS/N-doped carbon composite hollow spheres with excellent supercapacitor performance

Abstract: Designing electrode materials with high specific capacitance is crucial for further improving the energy storage performance of supercapacitors. Nickel sulfide (NiS) nanosheets anchored on the surface of N-doped hollow carbon spheres (NiS/NHCS) were rationally designed and synthesized via a multistep transformation approach. Uniform nickel silicate nanosheets were first deposited on the surface of NHCSs, followed by chemical conversion into NiS nanosheets. The NiS/NHCS composite shows excellent electrochemical properties as an electrode material for supercapacitors. The NiS/NHCS electrode can deliver a high specific capacitance of 1150 F g−1 at 1 A g−1 and show outstanding cycling performance with a retention rate of 76% over 4000 cycles, which are much higher than those of pure NiS hollow spheres (NiS-HS) (400 F g−1 and 63%, respectively). Moreover, a hybrid supercapacitor assembled with NiS/NHCS as the cathode and an activated carbon electrode as the anode delivers a high energy density of 38.3 W h kg−1 at a power density of 160 W kg−1 and has an excellent cycle performance with the retention rate of 96% after 5000 cycles. The exceptional electrochemical performance of the NiS/NHCS composite indicates its potential application in high-performance supercapacitors.

Ultra-fast firing: Effect of heating rate on sintering of 3YSZ, with and without an electric field

Abstract: It has recently been reported that ceramics can be sintered in a few seconds with the aid of an electric field (“flash sintering”). This investigation tests the possibility that the accelerated sintering is a consequence of the rapid heating rate involved rather than a direct effect of the electric field on mass transport. The sintering of 3YSZ powder compacts at a temperature of ∼1300 °C was compared (i) in flash sintering, (ii) with rapid heating rates produced without the application of an electric field, and (iii) with conventional heating rates. The results show that rapid heating can accelerate sintering by over 2 orders of magnitude compared with heating to the same temperature at conventional rates, even without the application of an electric field. It is concluded that the rapid densification in flash sintering of 3YSZ is at least partly a consequence of the rapid heating involved. Possible explanations are discussed.