Mn 3 O 4 nanocrystalline/graphene hybrid electrode with high capacitance

Producing "Symbiotic" Reduced Graphene Oxide/Mn3O4 Nanocomposites Directly from Converting Graphite for High-Performance Supercapacitor Electrodes

Almost all existing methods for preparing reduced graphene oxide/Mn₃O₄ (RGO/Mn₃O₄) composites are based on the synthetized graphene or graphene oxides (GO), which make them complicated and high-cost processes. Here, we reported a new method, which is able to convert graphite directly to RGO/Mn₃O₄ composites. Thus, it is simpler, more economical, and productive. The structure of RGO/Mn₃O₄ inheriting intermediate product GO/MnO₂ composites that are formed by the present method is a novel three-dimensional "multilayer steamed bread" nanostructure, which constitutes mutually beneficial "symbiosis". The nano-Mn₃O₄ supports the space between RGO layers and further to the combination of RGO to self-assemble into large-sized (>40 μm) nanocomposites. Meanwhile, the formed Mn₃O₄ particles were small (60 × 10 nm²) in diameter and distributed homogeneously without the use of any template and surfactant. Because the structure and nanosize of composite cause the excellent electrochemical properties, RGO/Mn₃O₄ electrodes deliver an enhanced specific capacitance of 438.7 F/g at 0.3 A/g and outstanding cyclic stability (77.5% of its initial capacitance is retained after 1000 cycles).

In situ mass change and gas analysis of 3D manganese oxide/graphene aerogel for supercapacitors

Manganese oxide nanoparticles decorated on 3D reduced graphene oxide aerogels (3D MnO_x/rGO_ae) for neutral electrochemical capacitors were successfully produced by a rapid microwave reduction process within 20 s.

Synthesis of graphene-transition metal oxide hybrid nanoparticles and their application in various fields

Single layer graphite, known as graphene, is an important material because of its unique two-dimensional structure, high conductivity, excellent electron mobility and high surface area. To explore the more prospective properties of graphene, graphene hybrids have been synthesised, where graphene has been integrated with other important nanoparticles (NPs). These graphene-NP hybrid structures are particularly interesting because after hybridisation they not only display the individual properties of graphene and the NPs, but also they exhibit further synergistic properties. Reduced graphene oxide (rGO), a graphene-like material, can be easily prepared by reduction of graphene oxide (GO) and therefore offers the possibility to fabricate a large variety of graphene-transition metal oxide (TMO) NP hybrids. These hybrid materials are promising alternatives to reduce the drawbacks of using only TMO NPs in various applications, such as anode materials in lithium ion batteries (LIBs), sensors, photocatalysts, removal of organic pollutants, etc. Recent studies have shown that a single graphene sheet (GS) has extraordinary electronic transport properties. One possible route to connecting those properties for application in electronics would be to prepare graphene-wrapped TMO NPs. In this critical review, we discuss the development of graphene-TMO hybrids with the detailed account of their synthesis. In addition, attention is given to the wide range of applications. This review covers the details of graphene-TMO hybrid materials and ends with a summary where an outlook on future perspectives to improve the properties of the hybrid materials in view of applications are outlined.

Highly flexible all-solid-state cable-type supercapacitors based on Cu/reduced graphene oxide/manganese dioxide fibers

An all-solid-state Cu/RGO/MnO₂ fiber supercapacitor showed excellent capacitance and flexibility, and could serve as electrical cable and as energy storage device.

Facile synthesis of diverse transition metal oxide nanoparticles and electrochemical properties

Four diverse metal oxide nanoparticles are synthesized successfully and CoO nano-cubes show excellent electrochemical properties.