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

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The broadband and tunable high-performance microwave absorption properties of an ultralight and highly compressible graphene foam (GF) are investigated. Simply via physical compression, the microwave absorption performance can be tuned. The qualified bandwidth coverage of 93.8% (60.5 GHz/64.5 GHz) is achieved for the GF under 90% compressive strain (1.0 mm thickness). This mainly because of the 3D conductive network.

Broadband and Tunable High‐Performance Microwave Absorption of an Ultralight and Highly Compressible Graphene Foam

https://iopscience.iop.org/article/10.1088/1468-6996/16/2/023501/pdf

Recent progress on magnetic iron oxide nanoparticles: synthesis, surface functional strategies and biomedical applications.

ZnS nanostructures: From synthesis to applications

Microwave absorbing properties of a thermally reduced graphene oxide/nitrile butadiene rubber composite

Synthesis and photoluminescent properties of ZnS nanocrystals doped with copper and halogen

Alternate-current electroluminescent (ac EL) devices based on doped ZnS nanocrystals emitting blue, green, and orange-red colors are reported. ZnS nanocrystals doped with Cu+ – Al3+ and Cu+ – Al3+ – Mn2+ combinations were synthesized by wet chemical method at room temperature. The ZnS:Cu+, Al3+ nanocrystals show blue (462 nm) and green (530 nm) EL emissions depending upon the presence and absence of sulphur vacancies, respectively. The orange EL emission (590 nm) is realized from ZnS:Cu+, Al3+, Mn2+ nanoparticles by way of nonradiative energy transfer from AlZn – CuZn pairs to MnZn. The EL devices show low turn-on voltage of ~10 V ac @100 Hz. The mechanism of ac EL in ZnS nanocrystals has been explained wherein the excitation is attributed to the electric-field-assisted injection of electron-hole pairs from the surface regions into the interiors and their subsequent recombination therein causes emission.

/pdf/multicolor-electroluminescent-devices-using-doped-zns-2c8wyo253f.pdf

Multicolor electroluminescent devices using doped ZnS nanocrystals

In situ synthesis of graphene oxide and its composites with iron oxide

In the present paper, we report electrical conductivity and dielectric studies on the composites of conducting polyaniline (PANI) with crystalline semiconducting ZnS powder, wherein PANI has been taken as inclusion and ZnS crystallites as the host matrix. From the studies, it has been observed that the value of room temperature d.c. conductivity of the composites with volume fraction of PANI > 0.65 shows an unusual behaviour wherein, conductivity values of the composites exceed that of PANI itself with maximum value as high as 6 times that of PANI at the volume fraction of 0.85. A similar trend has also been observed for the real and imaginary parts of complex dielectric constant values of the composites. This unusual behaviour in the d.c. conductivity and dielectric properties has been attributed to the enhancement in the degree of crystallinity of PANI as a consequence of its interfacial interaction with ZnS matrix. The results of optical microscopy show coating of PANI all around the ZnS particles. The temperature dependent conductivity studies suggest the quasi one-dimensional VRH conduction in PANI as well as its composites with ZnS. FTIR and XRD studies have also been reported.

/pdf/studies-on-conductivity-and-dielectric-properties-of-poi0dgeoix.pdf

Sampat Raj Vadera

Papers

Microwave absorbing properties of a thermally reduced graphene oxide/nitrile butadiene rubber composite

Synthesis and photoluminescent properties of ZnS nanocrystals doped with copper and halogen

Multicolor electroluminescent devices using doped ZnS nanocrystals

In situ synthesis of graphene oxide and its composites with iron oxide

Studies on conductivity and dielectric properties of polyaniline-zinc sulphide composites