Volume 5, Issue 4 - Special issue: Graphene / Guest Editor: Narayan S. Hosmane

Graphene, a perfect lattice of hexagonally arranged carbon atoms, is currently among the most intensively researched material because of its mechanical, electronic, optical, and DNA-binding properties, and has found enormous applications in electronics, transistors, sensors, photovoltaics, optical and biological materials, among others. Many recent studies have established that graphene, in combination with other non-carbon nanoparticles, yields hybrid materials with improved properties. Graphene-boron nanohybrids are one such class of materials with alluring properties currently reported to be more advantageous than graphene as such. This review is intended to present a brief discussion about graphene, other carbon nanoallotropes, and a compilation of carbon nanoallotropes-boron nanoparticle hybrids much envisioned to expedite the boron-graphene hybrid research. We have attempted to present recent developments in these boron-based hybrid structures of carbon nanoallotropes, and augment the need for such advantageous materials.

Graphene oxide (GO) macroscopic films, fibers, and membranes have become important applications of this interesting two-dimensional material due to their specific properties and great potential as new high-performance materials. After chemical or thermal reduction, GO is transformed into an electrically conductive material termed reduced GO (RGO). These materials hold great potential because they can be prepared in large quantities at low costs, and consequently they are particularly suitable for applications in packaging, textiles, energy devices, and separation technologies. In the following years, the use of GO- and RGO-based films, fibers, and membranes is expected to grow; however, several challenges regarding its processing conditions must be resolved. In this review, we addressed some of the recent work regarding these important technologies and summarized the state of the art of GO films, fibers, and membranes.

Graphene is a two-dimensional material with amazing characteristics, which grant it the title “wonder material”. It has grabbed appreciable attention due to its exceptional electrical, optical, thermal, and mechanical properties. Because of these interesting properties, graphene has found its way into a wide variety of biosensing applications. It has been used as a transducer in electrochemical biosensors, bio-field-effect transistors, impedance biosensors, electrochemiluminescence, and fluorescence biosensors. Functionalization of graphene has further opened up novel fundamental and applied frontiers. The present article reviews recent works dealing with synthesis, functionalization of graphene, and its applications related to biosensors. Various synthesis strategies, mechanism and process parameters, and types of functionalization are discussed in view of biosensor development. Some potential areas for biosensor-related applications of functionalized graphene are highlighted, including catalytic biosensors and bio affinity biosensors. Wherever applicable, the limitations of the present knowledgebase and possible research directions have also been discussed.

Graphene-titanium dioxide (TiO 2 ) hybrid nanomaterials have received much attention due to their high potential in enhancing the photocatalytic efficiency. In the hybrid system, graphene acts as an electron acceptor to ensure the fast charge transfer to the current collector. Three-dimensional (3D) graphene in this context represents a new format of graphene material to further enhance the photocatalytic efficiency. 3D graphene has been shown to be a good candidate for making hybrid materials due to its outstanding properties, including increased surface area, multiple conductivity pathways, absence of intersheet contact resistance, reduced agglomeration of two-dimensional (2D) graphene sheets, and ease of handling and control. The examples included in this chapter have shown the high potential of 3D graphene in developing high-efficiency photocatalysts based on 3D graphene-TiO 2 hybrid nanomaterials.