Synthesis and characterization of Ag 2 S and Ag 2 S/Ag 2 (S,Se) NIR nanocrystals

RUIZ, DIEGO; MIZRAHI, MARTÍN; SANTOS, HARRISSON D. A.; JAQUE, DANIEL; JONES, CALLUM M. S.; MARQUÉS-HUESO, JOSÉ; JACINTO, CARLOS; REQUEJO, FÉLIX G.; TORRES-PARDO, ALMUDENA; GONZÁLEZ-CALBET, JOSÉ M.; JUÁREZ, BEATRIZ H.

Nanoscale

Royal Society of Chemistry

Lugar: Amsterdam; Año: 2019 vol. 11 p. 9194 - 9200

2040-3364

Syntheses of metal sulfide nanocrystals (NCs) by heat-up routes in the presence of thiols yield NC arrangements difficult to further functionalize and transfer to aqueous media. By means of different NMR techniques, and exemplified by Ag 2 S NCs, a metal-organic polymer formed during the synthesis acting as a ligand has been identified to be responsible for such aggregation. In this work, a new synthetic hot-injection strategy is presented to synthesize Ag 2 S NCs which are easily ligand exchangeable in water. Furthermore, the hot-injection route allows an extra NC treatment with Se to produce Ag 2 S/Ag 2 (S,Se) NCs with improved optical properties with respect to the Ag 2 S cores, and better resistance to oxidation, as demonstrated by X-ray absorption experiments.