Recent advancements in materials science have shed light on the potential of exploring hierarchical assemblies of molecules on surfaces, driven by both fundamental and applicative challenges. This field encompasses diverse areas including molecular storage, drug delivery, catalysis, and nanoscale chemical reactions. In this context, the utilization of nanotube templates (NTs) has emerged as promising platforms for achieving advanced one-dimensional (1D) molecular assemblies. NTs offer cylindrical, crystalline structures with high aspect ratios, capable of hosting molecules both externally and internally (Mol@NT). Furthermore, NTs possess a wide array of available diameters, providing tunability for tailored assembly. This review underscores recent breakthroughs in the field of Mol@NT. The first part focuses on the diverse panorama of structural properties in Mol@NT synthesized in the last decade. The advances in understanding encapsulation, adsorption, and ordering mechanisms are detailed. In a second part, the review highlights the physical interactions and photophysics properties of Mol@NT obtained by the confinement of molecules and nanotubes in the van der Waals distance regime. The last part of the review describes potential applicative fields of these 1D heterostructures, providing specific examples in photovoltaics, luminescent materials, and bio-imaging. A conclusion gathers current challenges and perspectives of the field to foster discussion in related communities.

Photoredox catalysis is becoming more and more prevalent in the 21st century as a new tool for organic and polymer synthesis. In addition, this domain clearly fits the expectations of the twelve principles of green chemistry. However, access to metal containing photosensitizers is not always straightforward and can require long reaction times, the use of toxic solvents and multi-step synthesis. These are definitely drawbacks that could be overcome with the use of novel technologies. In this report, we develop a one-pot two-step synthesis of iron(II) photosensitizers using ball-milling. Overall reaction times were drastically reduced, no solvent was needed during the reaction, and ten complexes could be isolated in high yields (73–99%). Using a transparent milling jar, the formation of the complexes could be followed using in situ Raman spectroscopy.

Carbon-based dots (CDs) are a novel class of luminescent carbon nanomaterials that have attracted much attention as promising alternatives for cadmium-based quantum dots and fluorescent organic dyes. Although different strategies have been proposed to produce CDs with intense and tuneable one-photon excited fluorescence (OPEF), the case of analogous two-photon excited fluorescence (TPEF) has not been fully explored yet. By varying the synthesis conditions, we produced three types of phloroglucinol-based carbon nanodots (PG CNDs). Their remarkable OPEF and TPEF properties can be tuned by (Ia) the conjugated aromatic domains and (Ib) the content of oxygenous moieties. In addition, the emission colour of the PG CNDs is strongly responsive to (II) the hydrogen-bonding network, enabling colour-switching while maintaining excellent fluorescence yields (both OPEF and TPEF). These three factors were evaluated for their suitability for the tuning of the emission colour. Our studies point out the advantages of the tuneable PG CNDs to be used in optoelectronics and biological application domains.

Sodium hexatitanate, Na 2 Ti 6 O 13 , in the form of elongated microcrystals, were synthesized by solid‐state reaction of titanium dioxide and sodium carbonate. The monoclinic structure was confirmed by X‐ray powder diffraction and selected area electron diffraction. Electron diffraction was used to determined zone axis and the crystal‐grown direction, which allowed to perform polarized Raman measurements. Energy band gap and the electronic transition were studied by UV–Vis diffuse reflectance and using Tauc relation. Density functional theory (DFT) calculations also revealed an indirect allowed bandgap transition and a good agreement between theoretical and experimental energy band gaps were demonstrated. For the first time, the assignment of the vibrational modes was carried out in the samples and thoroughly compared with theoretical data obtained from DFT calculations. The most relevant of the 60 predicted optical phonon modes of Na 2 Ti 6 O 13 were experimentally observed and assigned to their symmetries.

The unique physical, mechanical, chemical, optical, and electronic properties of hexagonal boron nitride (hBN) make it a promising two-dimensional material for electronic, optoelectronic, nanophotonic, and quantum devices.

Here we report on the changes in hBN's properties induced by isotopic purification in both boron and nitrogen. Previous studies on isotopically pure hBN have focused on purifying the boron isotope concentration in hBN from its natural concentration (approximately 20 at% 10 B, 80 at% 11 B) while using naturally abundant nitrogen (99.6 at% 14 N, 0.4 at% 15 N), i.e. almost pure 14 N. In this study, we extend the class of isotopically-purified hBN crystals to 15 N. Crystals in the four configurations, namely h 10 B 14 N, h 11 B 14 N, h 10 B 15 N, and h 11 B 15 N, were grown by the metal flux method using boron and nitrogen single isotope (>99%) enriched sources, with nickel plus chromium as the solvent.

In-depth Raman and photoluminescence spectroscopies demonstrate the high quality of the monoisotopic hBN crystals with vibrational and optical properties of the 15 N-purified crystals at the state of the art of currently available 14 N-purified hBN. The growth of high-quality h 10 B 14 N, h 11 B 14 N, h 10 B 15 N, and h 11 B 15 N opens exciting perspectives for thermal conductivity control in heat management, as well as for advanced functionalities in quantum technologies.

Monodispersed hollow periodic mesoporous organosilica nanoparticles (HPMO-NPs) with a controlled core cavity and a periodic mesoporous organosilica (PMO) shell are successfully synthesized using a dual templating approach. The PMO shell synthesized by the sol–gel route exhibits a hybrid organic-inorganic framework based on phenylene bridges. The HPMO spherical nanoparticles with a diameter above 500 nm were characterized using a multiscale approach through TEM, BET, SAXS, and FT-IR. They are shown to offer an open periodic mesoporosity, a hollow cavity with a size tailored by thediameter of the core template, and finally, a high surface area (833 m 2 · g−1 ). In addition, we demonstrate that, through the same approach, the size of these hollow spherical nanoparticles can be tuned. Indeed, sub-50-nm hollow nanoparticles with mesoporous shells have also been obtained. The differences observed in the textural properties of these two sizes of hollow mesoporous nano-objects are discussed.