Ultra-High Energy Density Hybrid Supercapacitors Using MnO/Reduced Graphene Oxide Hybrid Nanoscrolls.

Manganese oxide (MnO) is a promising material for supercapacitor applications, with a theoretical ultra-high energy density of 308 Wh/kg. However, such ultra-high energy density has not been achieved experimentally in MnO-based supercapacitors because of several practical issues, such as low electrical conductivity of MnO, incomplete utilization of MnO, and dissolution of MnO The present study investigates the potential of MnO/reduced graphene oxide (rGO) hybrid nanoscroll (GMS) structures as electrode material for overcoming the difficulties and for developing ultra-high-energy storage systems. A hybrid supercapacitor, comprising MnO/rGO nanoscrolls as anode material and activated carbon (AC) as a cathode, is fabricated.

An Ultra-High-Energy Density Supercapacitor; Fabrication Based on Thiol-functionalized Graphene Oxide Scrolls.

Present state-of-the-art graphene-based electrodes for supercapacitors remain far from commercial requirements in terms of high energy density. The realization of high energy supercapacitor electrodes remains challenging, because graphene-based electrode materials are synthesized by the chemical modification of graphene. The modified graphene electrodes have lower electrical conductivity than ideal graphene, and limited electrochemically active surface areas due to restacking, which hinders the access of electrolyte ions, resulting in a low energy density.

Self-rectifying bipolar resistive switching memory based on an iron oxide and graphene oxide hybrid.

A resistive random access memory (RRAM) device with self-rectifying I-V characteristics was fabricated by inserting a silicon nitride (SiN) layer between the bottom electrode and solution-processed active material of an iron oxide-graphene oxide (FeO-GO) hybrid. The fabricated Au/Ni/FeO-GO/SiN/n-Si memory device exhibited an excellent resistive switching ratio and a rectification ratio higher than 10. In the Au/Ni/FeO-GO/SiN/n-Si device, resistive switching occurs in both the FeO-GO and SiN layers separately, resulting in a highly uniform and stable switching performance.

High Volumetric Energy Density Hybrid Supercapacitors Based on Reduced Graphene Oxide Scrolls.

The low volumetric energy density of reduced graphene oxide (rGO)-based electrodes limits its application in commercial electrochemical energy storage devices that require high-performance energy storage capacities in small volumes. The volumetric energy density of rGO-based electrode materials is very low due to their low packing density. A supercapacitor with enhanced packing density and high volumetric energy density is fabricated using doped rGO scrolls (GFNSs) as the electrode material.

Reduced graphene oxide enwrapped phosphors for long-term thermally stable phosphor converted white light emitting diodes.

The long-term instability of the presently available best commercial phosphor-converted light-emitting diodes (pcLEDs) is the most serious obstacle for the realization of low-cost and energy-saving lighting applications. Emission from pcLEDs starts to degrade after approximately 200 h of operation because of thermal degradation of the phosphors. We propose a new strategy to overcome this thermal degradation problem of phosphors by wrapping the phosphor particles with reduced graphene oxide (rGO).

Raman Spectra of Luminescent Graphene Oxide (GO)-Phosphor Hybrid Nanoscrolls.

Graphene oxide (GO)-phosphor hybrid nanoscrolls were synthesized using a simple chemical method. The GO-phosphor ratio was varied to find the optimum ratio for enhanced optical characteristics of the hybrid. A scanning electron microscope analysis revealed that synthesized GO scrolls achieved a length of over 20 μm with interior cavities.

Graphene oxide-phosphor hybrid nanoscrolls with high luminescent quantum yield: synthesis, structural, and X-ray absorption studies.

Highly luminescent graphene oxide (GO)-phosphor hybrid thin films with a maximum quantum yield of 9.6% were synthesized via a simple chemical method. An intense luminescence emission peak at 537 nm and a broad emission peak at 400 nm were observed from the GO-phosphor hybrid films.