Multivalency-induced structural variations of 2D selenium nanosheets: facile solution-phase synthesis and optical properties.

The structural stability of two-dimensional (2D) phases derived from bulk selenium (Se) is intrinsically rooted in the multivalent nature of the material. The emergence of 2D Se, as its morphology evolves from 1D to 2D, was initially inspired by theoretical predictions of various quasi-stable structural phases of 2D Se. Here, we report a facile liquid-phase synthesis of free-standing few-layer selenium nanosheets (SeNS) employing a simple magnetic stirring of their bulk counterpart in -methyl pyrrolidone (NMP).

Comparative photoluminescence study of nitrogen-doped carbon dots co-doped with boron and sulphur.

Although different studies in carbon dots (CDs) have been reported based on heteroatom doping, most of them have focussed on the enhancement of fluorescence properties. Here we report a comparative study of both fluorescence and room-temperature phosphorescence (RTP) of nitrogen-sulphur-doped CDs (N-S CDs) and nitrogen-boron-doped CDs (N-B CDs) with N-doped CDs (N CDs). The CDs used in the study were synthesized through microwave-assisted pyrolysis.

Facile synthesis of aqueous-dispersed luminescent nanosheets from non-layered lanthanum hexaboride.

Two-dimensional nanosheets of non-layered materials have been considered as inaccessible through exfoliation techniques, due to their intrinsic three-dimensional lattice structure. Herein we report the successful synthesis of nanosheets from non-layered, lanthanum hexaboride through a facile, solution-assisted, surfactant-free, sonication. The morphological studies clearly show the presence of nanosheets having thickness of a few nanometers, and having lateral dimensions of several hundreds of nanometres.

Cool white, persistent room-temperature phosphorescence in carbon dots embedded in a silica gel matrix.

Herein we report the observation of room-temperature phosphorescence from carbon dots (CDs) embedded in a silica gel matrix. The precursors used in the synthesis (malonic acid and ethylene diamine) were chosen to have the surface of the CDs rich in C[double bond, length as m-dash]O and C[double bond, length as m-dash]N functionalities. The CDs in an aqueous dispersion exhibit an intense blue fluorescence and upon incorporation into silica gel demonstrate a green after-glow, which is visible even to the naked eye.

White-Light-Emitting Carbon Dots Prepared by the Electrochemical Exfoliation of Graphite.

The single-step synthesis of white-light-emitting carbon dots (CDs) through a green, facile and cheap electrochemical route by using graphite rods as the carbon source is reported. Under UV excitation, the aqueous dispersion of as-synthesised CDs exhibit broad-band emission, which covers a significant fraction of the visible spectrum, owing to the heterogeneity in particle size and surface functional groups. The CDs were further explored for their potential as UV-to-visible colour convertors under remote-phosphor technology by capping a λ=365 nm UV light-emitting diode (LED) chip with CD-loaded poly(methyl methacrylate) to obtain the following colour parameters: Commission Internationale de l'Eclairage chromaticity coordinates (0.