Unraveling the Facet-Dependent Surface Chemistry at Molecular Scale: Photoassisted Oxidation of InP Nanocrystals
Year: 2024
Type: article
Abstract: The facet-dependent surface chemistry of nanocrystals (NCs) provides fundamental insights into chemical reactivities, which are critical for obtaining precise control over the NC surface. In this study, by obtaining InP NCs with well-defined {111} and {110}/{−1–1–1} facets (tetrahedrons and tetrapods, respectively) capped with chloride-oleylamine ligands, the previously underinvestigated facet-dependent surface chemistry of III–V materials is explored. Solid-state and solution NMR analyses show that InP tetrahedrons, with their smaller surface heterogeneity (single facet composition and lesser edge/vertex contribution) and stronger Lewis acidity, exhibit narrow 31 P and 115 In resonances as well as deshielded 13 C signals of α-carbon adjacent to the NH 2 group of oleylamine. As a result, InP tetrahedra exhibit strong ligand binding and a notable presence of less-mobile oleylamine ligands on the surface, leading to the blocking of access to external species. This is also consistent with the minimal blue shift of the first excitonic peak in absorption spectra and the strong resistance to photoassisted surface oxidation of InP tetrahedrons. Our findings, supported by solid-state/solution NMR, FT-IR, and XPS analyses, highlight the significance of facet-dependent reactivities to surface ligands and, thus, atmospheric moieties, enhancing the potential of III–V NCs in various optoelectronic applications.
DOI: 10.1021/jacs.4c10231
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funders: Indian National Science Academy, National Research Foundation, Agence Nationale de la Recherche, Ministère de l'Europe et des Affaires Étrangères, Korea Basic Science Institute, National Research Foundation of Korea, Ministère de l'Education Nationale, de l'Enseignement Superieur et de la Recherche, Centre National de la Recherche Scientifique, Université Toulouse III - Paul Sabatier, Ministry of Science and ICT, South Korea
Awards: G1473098024, G158080503, G1736502769, G1944285103, G2221794374, G2365361047, G2680084322, G3329698811, G3854687859, G4068580611, G4194327744, G4447581645, G4732306112, G478497978, G5243390624, G5253391959, G5961346375, Luminescence Nanothermometry for the control and understanding of magneto-induced process. Application to biological hyperthermia and heterogeneous catalysis in solution, G7353414468, G7600850694, G7920874134, G7957099457, G8067211302, G8336030396, G8532821287, G8655223509
OpenAlex ID: W4404221936