Light Conversion upon Photoexcitation of NaBiF:Yb/Ho/Ce Nanocrystalline Particles.

NaBiF nanocrystalline particles were synthesized by means of a facile precipitation synthesis route to explore upconversion emission properties when doped with lanthanide ions. In particular, the incorporation of the Yb-Ho-Ce triad with controlled ion concentration facilitates near-IR pumping conversion into visible light, with the possibility of color emission tuning depending on Ce doping amount. We observed that introducing a Ce content up to 20 at.

Confined-Melting-Assisted Synthesis of Bismuth Silicate Glass-Ceramic Nanoparticles: Formation and Optical Thermometry Investigation.

Bismuth-based (nano)materials have been attracting increasing interest due to appealing properties such as high refractive indexes, intrinsic opacity, and structural distortions due to the stereochemistry of 6s lone pair electrons of Bi. However, the control over specific phases and strategies able to stabilize uniform bismuth-based (nano)materials is still a challenge. In this study, we employed the ability of bismuth to lower the melting point of silica to introduce a new synthetic approach able to confine the growth of bismuth-oxide-based materials into nanostructures.

Precursor-Dependent Photocatalytic Activity of Carbon Dots.

This work systematically compares both structural features and photocatalytic performance of a series of graphitic and amorphous carbon dots (CDs) prepared in a bottom-up manner from fructose, glucose, and citric acid. We demonstrate that the carbon source and synthetic procedures diversely affect the structural and optical properties of the CDs, which in turn unpredictably influence their photo electron transfer ability. The latter was evaluated by studying the photo-reduction of methyl viologen.

BiSiO@g-SiO upconverting nanoparticles: a bismuth-driven core-shell self-assembly mechanism.

Core-shell systems have attracted increasing interest among the research community in recent years due to their unique properties and structural features, and the development of new synthetic strategies is still a challenge. In this work, we have investigated lanthanide-doped Bi2SiO5 nanocrystal formation inside mesoporous silica nanoparticles (MSNs). The role of both synthesis temperature and concentration of the bismuth precursor impregnated into the MSNs is discussed, showing an unprecedented strategy for the simultaneous stabilization of a crystalline core and a glassy shell.

Tuning the upconversion light emission by bandgap engineering in bismuth oxide-based upconverting nanoparticles.

In the field of novel applications involving upconverting processes, the determination of new strategies for realizing emission-tunable nanomaterials is a challenge. In this work the design of Y and Er codoped bismuth oxide-based upconverting nanoparticles is presented, evidencing that the active role of the matrix allows for the emission selectivity with chromaticity control. The bandgap of the bismuth oxide-based host can be manipulated in the range of 0.