Impact of capping agent on microstructural and optoelectronic properties of ZnS nanoparticles

Equimolar As4S4/Fe3O4 Nanocomposites Fabricated by Dry and Wet Mechanochemistry: Some Insights on the Magnetic–Fluorescent Functionalization of an Old Drug

“…Similarly, the donor level of the interstitial As atom in the upper part of the bandgap (I As ) is operational rather as the As 2 − defect, whereas the acceptor level of the interstitial S atom (I S ) in the bottom of the bandgap behaves like the S 3 + defect. The fluorescence properties of the NPs possessing a QCE are known to be strongly dependent on the interfacial processes at the boundaries between the nanocrystallites and the surrounding medium [25,26]. The complete disappearance of fluorescence in the surfactantcapped β-As 4 S 4 /Fe 3 O 4 -PX nanocomposite after one year of natural storage testifies in favor of a substantial degradation of such interface states ascribed to arsenical nanocrystallites possessing CFE.…”

“…Such a bimodal "two-in-one" functionalization foresees the surface passivation of arsenical NPs, which contribute to the non-radiative recombination from the surface states of dangling bonds (DBs), like in other nanostructured substances [25]. Noteworthily, NPs with non-passivated surfaces (stabilized in the MNP systems without surfactants) are prone to quick agglomeration and oxidation, thereby missing with time a size-limiting requirement for a quantum confinement effect (QCE) [12,[24][25][26].…”