Metal Oxides and Oxysalts as Anode Materials for Li Ion Batteries

Graphene, a two-dimensional, single-layer sheet of sp(2) hybridized carbon atoms, has attracted tremendous attention and research interest, owing to its exceptional physical properties, such as high electronic conductivity, good thermal stability, and excellent mechanical strength. Other forms of graphene-related materials, including graphene oxide, reduced graphene oxide, and exfoliated graphite, have been reliably produced in large scale. The promising properties together with the ease of processibility and functionalization make graphene-based materials ideal candidates for incorporation into a variety of functional materials. Importantly, graphene and its derivatives have been explored in a wide range of applications, such as electronic and photonic devices, clean energy, and sensors. In this review, after a general introduction to graphene and its derivatives, the synthesis, characterization, properties, and applications of graphene-based materials are discussed.

Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications

Graphene/metal oxide composite electrode materials for energy storage

We developed two-step solution-phase reactions to form hybrid materials of Mn3O4 nanoparticles on reduced graphene oxide (RGO) sheets for lithium ion battery applications. Mn3O4 nanoparticles grown selectively on RGO sheets over free particle growth in solution allowed for the electrically insulating Mn3O4 nanoparticles wired up to a current collector through the underlying conducting graphene network. The Mn3O4 nanoparticles formed on RGO show a high specific capacity up to ~900mAh/g near its theoretical capacity with good rate capability and cycling stability, owing to the intimate interactions between the graphene substrates and the Mn3O4 nanoparticles grown atop. The Mn3O4/RGO hybrid could be a promising candidate material for high-capacity, low-cost, and environmentally friendly anode for lithium ion batteries. Our growth-on-graphene approach should offer a new technique for design and synthesis of battery electrodes based on highly insulating materials.

Mn3O4-Graphene Hybrid as a High Capacity Anode Material for Lithium Ion Batteries

Graphene-based materials for catalysis

This paper reports on the synthesis of Co3O4@graphene composites (CGC) and their applications as anode materials in lithium ion batteries (LIBs). Through a chemical deposition method, Co3O4 nanoparticles (NPs) with sizes in the range of 10−30 nm were homogeneously dispersed onto graphene sheets. Due to their high electrical conductivity, the graphene sheets in the CGC improved the electrical conductivity and the structure stability of CGC. CGC displayed a superior performance in LIBs with a large reversible capacity value of 941 mA hg−1 in the initial cycle with a large current density and an excellent cyclic performance of 740 mA hg−1 after 60 cycles, corresponding to 88.3% of the theoretical value of CGC, owing to the interactions between graphene sheets and Co3O4 NPs anchored on the graphene sheets. This synthesis approach may find its application in the design and synthesis of novel electrode materials used in LIBs.

Co3O4@graphene Composites as Anode Materials for High-Performance Lithium Ion Batteries

Cu2O@reduced graphene oxide composite displays a good ability to remove dyes from water and high stability in supercapacitors, highlighting potential applications in environmental and energy storage issues.

Cu2O@reduced graphene oxide composite for removal of contaminants from water and supercapacitors

The Mg(OH)2@reduced graphene oxide (rGO) composite (MGC) was synthesized via a chemical deposition method Its mesoporous structures and application as an adsorbent for the removal of methylene blue (MB) from water were investigated The Mg(OH)2 nanosheets were formed and dispersed homogeneously onto the surface of rGO sheets, which provided high surface area, pore volume, and uniform pore width distribution MGC exhibited excellent adsorption behavior for MB

Mg(OH)2@reduced graphene oxide composite for removal of dyes from water

We report here a facile strategy to synthesize the nanocomposite of adenine-modified reduced graphene oxide (AMG) via reaction between adenine and GOCl which is generated from SOCl2 reacted with graphite oxide (GO). The as-synthesized AMG was characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), UV–vis absorption spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and galvanostatic discharge analysis. The AMG owns about one adenine group per 53 carbon atoms on a graphene sheet, which improves electronic conductivity compared with reduced graphene oxide (RGO). The AMG displays enhanced supercapacitor performance compared with RGO accompanying good stability and good cycling behavior in the supercapacitor.

Synthesis of Adenine-Modified Reduced Graphene Oxide Nanosheets

Here, we report on the synthesis of α-Mn2O3 complex nanostructures through heat-treatment of the precursor MnCO3 (in similar structure and size) synthesized by a biomineralization route. The phase, microstructure, and morphology of the obtained sample were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectrum, Raman spectrum, and scanning electron microscopy (SEM). The self-assembly mechanism of the precursor of MnCO3 is discussed. The α-Mn2O3 show two weak antiferromagnetic transition Neel temperatures at ∼78.3 and ∼15.8 K and a Curie–Weiss temperature at 48.5 K. Also, the α-Mn2O3 hierarchical nanostructures present superhydrophobicity with a contact angle over 150°.

Gui Yin

Papers

Co3O4@graphene Composites as Anode Materials for High-Performance Lithium Ion Batteries

Cu2O@reduced graphene oxide composite for removal of contaminants from water and supercapacitors

Mg(OH)2@reduced graphene oxide composite for removal of dyes from water

Synthesis of Adenine-Modified Reduced Graphene Oxide Nanosheets

Biomineralization Strategy to α-Mn2O3 Hierarchical Nanostructures