Themed collection JMC C Top Picks collection: The many faces of carbon

Nazario Martín introduces a Journal of Materials Chemistry C Top Picks web collection on “the many faces of carbon”.

Graphene, a monolayer of carbon atoms arranged in a honeycomb structure, is a unique material with outstanding properties that may be useful in applications ranging from electronic devices to energy storage devices.

Carbon quantum dots (CQDs, C-dots or CDs), which are generally small carbon nanoparticles (less than 10 nm in size) with various unique properties, have found wide use in more and more fields during the last few years. In this feature article, we describe the recent progress in the field of CQDs, focusing on their synthetic methods, size control, modification strategies, photoelectric properties, luminescent mechanism, and various applications.

Describing all the optical and electronic interactions of graphene with poly-aromatic molecules and polymers for electronic devices.

Ultrathin graphene, a 2D material, demonstrates outstanding features and rapid growth for EMI shielding due to its strong absorption towards electromagnetic waves in composites. It is sought after for communication, electronic devices, information security, electromagnetic pollution defense and healthcare.

A new strategy is developed to significantly enhance polymer thermoelectric property by the construction of 3D interconnected architecture consisting of rGO nanolayers sandwiched by PPy nanowires.

N-doped CDs can be obtained directly with high yield by pyrolyzing ethanolamine in air within just 7 minutes with the assistance of hydrogen peroxide.

Photoluminescence of graphene quantum-dot can be sensitively tuned by size, edge configurations, shape, chemical functionalities, defects, heteroatom-doping and hybridization states.

The rod-like structure of MnO₂@Fe is apt to convert the electromagnetic wave to microcurrent and then attenuate it.

Fluorescent carbon dots prepared by a heat treatment of ethylene glycol solution can act as fluorescence turn-on probes for sensitive and selective detection of Ag⁺ ions.

Nitrogen-doped carbon quantum dots (N-CQDs) prepared via a one-step hydrothermal reaction exhibited highly selective and sensitive detection of Hg²⁺ and I⁻ through fluorescence quenching and recovery processes, respectively.

A new strategy for in situ formation and separation of fluorescent N-GQDs for Fe³⁺ sensing was developed, with MOFs as precursors.

We developed a facile one-step route for the synthesis of blue fluorescent OS-GCNQDs, which exhibited improved selectivity and sensitivity for Hg²⁺ detection, and lower cytotoxicity for cell imaging.

A carbon-bridge effect was adopted to explain the electromagnetic wave absorbing property related to the cross-linked framework structure of RGO–SCI composites.

Carbon dots are prepared via pyrolysis of natural hair, and further embedded in a polymer matrix to prepare multidimensional hybrid materials.

Synergistic combination of metal nanoparticles and graphene modulates electronic properties of graphene, leading to enhancement in gas sensitivity and selectivity.

Novel conductive ultrathin graphene papers demonstrate effective EMI shielding of ∼46.3 dB (∼0.3 mm) and ∼47.7 dB (∼0.1 mm) in attenuators.

The level of nitrogen doping of graphene strongly depends on the type of the starting graphite oxide and temperature used.

Ultrafast electron transfer is identified from carbon nanodots to graphene oxide with a time constant of 400 fs.

With a view to developing flexible solid-state asymmetric supercapacitors, we have specially designed and nanoscopically engineered two types of electrodes: a MnO₂/ZnO core–shell nanorod array and a HI-reduced graphene oxide assembly, both deposited in situ on a carbon cloth.

Low temperature inkjet printing of exfoliated nanosheets has been demonstrated leading to conductive graphene traces and all-inkjet printed devices.