We report the formation of nickel borides, at room temperature and pressure, from the decomposition of NaBH(4) promoted by the addition of nickel bromide at different concentrations in a dispersing organic medium, tetrahydrofuran and pentane. The nickel borides, formed as amorphous powders, were analyzed, and the structure information served as input for modeling a periodic lattice structure with the same composition. Experimentally, the nickel boride phases were predominantly composed of a boron-rich phase with composition NiB(3). Combining FT-IR, X-ray diffraction analyses, and theoretical structure determination, we suggest for it a monoclinic structure, with symmetry group P2(1)/c, lattice parameters a =3.038 Å, b = 8.220 Å, c = 5.212 Å, α = β = 90.00° and γ = 87.57°. The enthalpies of formation of the nickel boride phases, as well as the lattice stability, were calculated using density functional theory and density functional perturbation theory methods.

The advents in flexible and smart technology like wearable electronics have accelerated the demand for high‐performance energy‐storage devices. These devices could significantly reduce the size of the next‐generation wearable smart electronics. A selection of suitable printing technology and its product typically offer a reasonable manufacturing pathway like high deposition rate, low materials waste, scalable fabrication, and high‐performance production. Therefore, the production of novel functional inks with desirable rheological properties that authorize high‐resolution printing, are some major challenges of this technology. This work has an emphasis on the recent advancements in supporting and utilizing liquid metals chemistry to synthesis high‐quality and scalable 2D nanomaterials by liquid‐phase free exfoliation and facile sonication‐assisted methods. These are novel concepts in synthesizing 2D nanomaterials particularly for those which either have not intrinsic layered crystal structures or those with strong interaction between their crystal layers which are difficult to synthesized using conventional approaches. It also provides some potentials to make sustainable ink formulation of such 2D nanostructures for the fabrication of high‐quality screen‐printed patterns for sustainable energy applications. Subsequently, it deals with the possibilities and challenges of printing such 2D nanomaterials (namely, 2D metal oxides) for micro‐supercapacitor and micro‐battery applications on an industrially viable scale.

This communication reports a size-controlled synthesis of water-soluble 2,2'-diphenyl-1-picrylhydrazyl (DPPH) nanoparticles (NPs). These nanoparticles exhibit size-dependent absorption spectra and fast spin exchange-narrowed single-line EPR spectra. The linewidths of the EPR spectra of these water-soluble nanoparticles are approximately 1.5-1.8 G, which are equal or close to the narrowest line width (1.5 G) of the common DPPH standard in the form of water-insoluble microcrystals. In addition, these NPs are stable over a wide pH range of 3.0 to 10.0. These properties make these water-soluble DPPH NPs suitable for use as a new type of EPR standard, which is important for fundamental research and practical applications in fields such as the food industry and the life sciences. Furthermore, the DPPH NPs can potentially be used as a spin probe in biomedical studies.

An ultrafast route to prepare up-converting single β-phase NaYF:Yb,Ln (Ln: Er, Tm, or Tb) short nanorods (UCNRs) of high quality was developed. This new procedure affords reactive-surface nanorods that are easily coated by direct injection of suitable capping ligands. Thus highly crystalline nanorods with excellent UC fluorescence and good solvent-selective dispersion are obtained, which represents a significant advance in the field and enlarges their use for biomedical and other technological applications. Unlike other methodologies, the short reaction time provides a kinetic control over crystallization processes, and the β-phase and rod morphology is preserved regardless of the optically active Ln ion. The UC emission was finely tuned by using the most popular Yb/Tm and Yb/Er pairs. More importantly, UCNRs doped with the unusual Yb/Tb pair, with no ladder-like energy levels, provided a nice emission upon near-infrared excitation, which constitutes the first example of phonon-assisted cooperative sensitization to date in pure β-NaYF nanocrystals.

Multimodal light-harvesting soft systems able to absorb UV-to-NIR radiations and convert into visible emissions have drawn much attention in the last years in order to explore new areas of application in energy, photonics, photocatalysis, sensors and so forth. Here, we present a new hybrid system combining a supramolecular photonic gel of naphthalimide-derived molecules self-assembled into fibers and upconverting NaYF 4 :Yb/Tm nanoparticles (UCNPs). The hybrid system presented here manipulates light reversibly as a result of an optical communication between the UCNPs and the photoactive gel network. Upon UV irradiation, the system shows the characteristic emission at 410 nm from the photoactive organomolecule. This emission is also activated upon 980 nm excitation thanks to an efficient energy transfer from the UCNPs to the fibrillary network. Interestingly, the intensity of this emission is thermally regulated during the reversible assembly or disassembly of the organogelator molecules, in such a way that gelator emission is only observed in the aggregated state. Additionally, the adsorption of the UCNPs with the supramolecular gel fibers enhance their emissive properties, a behavior ascribed to the isolation from solvent quenchers and surface defects, as well as an increased IR light scattering promoted by the fibrillary network. The reported system constitutes a unique case of a thermally regulated, reversible, dual UV and IR light harvesting hybrid soft material.3