Synergistic Effect Of Nickel Research Articles

Synergistic effect of cobalt and nickel on the superior electrochemical performances of rGO anchored nickel cobalt binary sulfides

Reduced graphene oxide (rGO) anchored spinel nickel cobalt binary sulfides nanosheets (NixCo3-xS4/rGO) with sandwich-like structure are synthesized via a facile hydrothermal process. The synergistic effect of nickel and cobalt on the superior electrochemical properties of the NixCo3-xS4/rGO nanocomposites is firstly illustrated in detail through the comparison of the phase structures, metal valent states and electrochemical behaviors of the nickel doped cobalt sulfide (Ni0.3Co2.7S4/rGO), cobalt doped nickel sulfide (Ni2.7Co0.3S4/rGO) and nickel cobalt binary sulfide (Ni1.5Co1.5S4/rGO). Results indicate that the fast valence change of nickel species mainly contributes the faradaic reaction of the active materials, while the cobalt species offer the high electronic conductivity and assist the charge transfer process. Due to the synergistic effect of cobalt and nickel, the Ni1.5Co1.5S4/rGO electrode with sandwich-like structure exhibits superior electrochemical performances, such as high specific capacity (347.5mAhg−1 based on metal sulfide), high areal specific capacity (4.3mAhcm−2), high cyclic stability (85.0% retention after 2000 cycles). An asymmetric device, with the Ni1.5Co1.5S4/rGO as positive material and a home-made activated carbon as negative material, delivers high energy density of 61.6Whkg−1 at the power density of 563.1Wkg−1 and still remains 49.3Whkg−1 even at high power density of 11.0kWkg−1.

Synergistic Effect of Nickel and Mercury on Fatty Acid Composition in the Muscle of Fish Lates calcarifer

Synergistic Effect of Nickel and Mercury on Fatty Acid Composition in the Muscle of Fish Lates calcarifer

Supported Nickel–Cobalt Bimetallic Catalysts Derived from Layered Double Hydroxide Precursors for Selective Hydrogenation of Pyrolysis Gasoline

Generation of bimetallic sites on supported catalysts has been proved to be capable of enhancing catalytic performance when compared to those of the corresponding monometallic ones. Herein we report the preparation of novel Al2O3-supported NiCo bimetallic catalysts (NiCo/Al2O3) derived from Ni2+Co2+Al3+-containing layered double hydroxides (NiCoAl-LDHs) precursors, which were in situ grown on the surface and in the pore canals of microspherical γ-Al2O3, and their catalytic performance for selective hydrogenation of pyrolysis gasoline. Bimetallic NiCo/Al2O3 derived from LDHs precursor exhibited the better catalytic performance than the sample prepared by impregnation. The appropriate amounts of substitution of nickel for cobalt improved the catalytic activity and stability dramatically, indicating the synergistic effects of nickel and cobalt in terms of the hydrogenation reactivity. The enhanced reducibility and smaller particles for NiCo/Al2O3 samples derived from LDHs precursor were proposed to suppress the coke formation during the hydrogenation reaction, leading to improve catalytic activity and stability.

Synthesis and improved electrochemical performances of nano β-NiMoO4–CoMoO4·xH2O composites for asymmetric supercapacitors

Nano-sized β-NiMoO4–CoMoO4·xH2O composites were synthesized by a solution combustion synthesis (SCS) technique. The effect of weight ratio of transition metal on the electrochemical capacitive performance of the nanocomposites was investigated by cyclic voltammetry and galvanostatic charge–discharge methods. The NiMoO4–CoMoO4·xH2O nanocomposite with weight ratio of 3:1 (Ni:Co) exhibits enhanced capacitive behaviour relative to other composites and delivered a maximum specific capacitance of 1472 Fg−1 at a current density of 5 mAcm−2. The enhancement in specific capacitance is due to the small particle size, uniform size distribution, high surface area and high weight fraction of Ni. The synergistic effect of nickel and cobalt improves the electrochemical behaviour relative to pure nickel and cobalt molybdates. A full cell was fabricated using the β-NiMoO4–CoMoO4·xH2O nanocomposite (3:1) and activated carbon (AC) as a positive and negative electrode, respectively. The cell delivered high capacitance (80 Fg−1) and energy density (28 Wh kg−1) and good cycling stability up to 1000 cycles.

Thermal Properties and Combustion Behaviors of Chitosan Based Flame Retardant Combining Phosphorus and Nickel

A renewable carbonization agent based compound nickel chitosan phosphate (NiPCS) has been prepared, which was the combination of flame retardant and synergist. Its effect on thermal properties and flammability of poly(vinyl alcohol) (PVA) has been investigated. Microscale combustion calorimetry (MCC) test proved that NiPCS can decrease the intensities of heat release rate (PHRR) and total heat release rate (THR) greatly. Thermogravimetric analysis (TGA) results indicated that NiPCS possessed a high formation of char. With the increase of the flame retardant, the thermal stability of materials enhanced in high temperature. Real time Fourier transform infrared (RT-IR) data confirmed that the flame retardant can promote the dehydration effect as well as accelerate the char forming. The volatilized products and the synergistic effect of nickel on thermal properties were both investigated with thermogravimetric analysis/infrared spectrometry (TGA-IR) and laser Raman spectroscopy (LRS). The results revealed that nickel restrained the thermal degradation of materials as well as improved the structural organization level of char.