No abstract

No abstract

No abstract

Co9S8, Ni3S2, and reduced graphene oxide (RGO) were combined to construct a graphene composite with two mixed metal sulfide components. Co9S8/RGO/Ni3S2 composite films were hydrothermal-assisted synthesized on nickel foam (NF) by using a modified "active metal substrate" route in which nickel foam acted as both a substrate and Ni source for composite films. It is found that the Co9S8/RGO/Ni3S2/NF electrode exhibits superior capacitive performance with high capability (13.53 F cm(-2) at 20 mA cm(-2), i.e., 2611.9 F g(-1) at 3.9 A g(-1)), excellent rate capability, and enhanced electrochemical stability, with 91.7% retention after 1000 continuous charge-discharge cycles even at a high current density of 80 mA cm(-2).

A “pseudocomposite” with unique nano-architecture of two Ni(OH)2/RGO layer was in situ synthesized on nickel foam (NF) using a facile onepot hydrothermal approach, which exhibits superior capacitive performance (15.65 F cm−2 at 7 mA cm−2, 90.6% capacity retention after 5000 cycles at 20 mA cm−2).

MOF-based substrates and their SERS applications.

Excitation of surface plasmon polaritons helps to increase the near-field heat flux by orders of magnitude beyond the limit governed by Stefan−Boltzmann law. However, the photon tunneling probability is rather low, except for modes satisfying the resonance condition of surface plasmon polaritons. Broadband hyperbolic metamaterials can broaden the frequency region for the enhancement of nearfield heat transfer, but can hardly maintain a high tunneling probability for large wavevectors since no resonances are excited to overcome the inherent exponential decay. In this letter, perfect photon tunneling with near-unity probability across broad frequency and k-space region is demonstrated based on the hybridization of graphene plasmons and hyperbolic modes. As a result, the near-field heat transfer coefficient between doped-silicon-nanowire hyperbolic metamaterials can be further improved several fold when covered by a graphene sheet, approaching to a theoretical limit.

No abstract