Dataset Information

Acidity of Carboxylic Acid Ligands Influences the Formation of VO₂(A) and VO₂(B) Nanocrystals under Solvothermal Conditions.

ABSTRACT: Vanadium dioxide (VO₂) can adopt many different crystal structures at ambient temperature and pressure, each with different, and often desirable, electronic, optical, and chemical properties. Understanding how to control which crystal phase forms under various reaction conditions is therefore crucial to developing VO₂ for various applications. This paper describes the impact of ligand acidity on the formation of VO₂ nanocrystals from the solvothermal reaction of vanadyl acetylacetonate (VO(acac)₂) with stoichiometric amounts of water. Carboxylic acids examined herein favor the formation of the monoclinic VO₂(B) phase over the tetragonal VO₂(A) phase as the concentration of water in the reaction increases. However, the threshold concentration of water required to obtain phase-pure VO₂(B) nanocrystals increases as the pK_a of the carboxylic acid decreases. We also observe that increasing the concentration of VO(acac)₂ or the concentration of acid while keeping the concentration of water constant favors the formation of VO₂(A). Single-crystal electron diffraction measurements enable the identification of vanadyl carboxylate species formed in reactions that do not contain enough water to promote the formation of VO₂. Increasing the length of the carbon chain on aliphatic carboxylic acids did not impact the phase of VO₂ nanocrystals obtained but did result in a change from nanorod to nanoplatelet morphology. These results suggest that inhibiting the rate of hydrolysis of the VO(acac)₂ precursor either by decreasing the ratio of water to VO(acac)₂ or by increasing the fraction of water molecules that are protonated favors the formation of VO₂(A) over VO₂(B).

SUBMITTER: Beidelman BA

PROVIDER: S-EPMC10588437 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Acidity of Carboxylic Acid Ligands Influences the Formation of VO2(A) and VO2(B) Nanocrystals under Solvothermal Conditions.

Beidelman Brittney A BA Zhang Xiaotian X Matson Ellen M EM Knowles Kathryn E KE

ACS nanoscience Au 20230622 5

Vanadium dioxide (VO2) can adopt many different crystal structures at ambient temperature and pressure, each with different, and often desirable, electronic, optical, and chemical properties. Understanding how to control which crystal phase forms under various reaction conditions is therefore crucial to developing VO2 for various applications. This paper describes the impact of ligand acidity on the formation of VO2 nanocrystals from the solvothermal reaction of ...[more]

PMID: 37868226

Similar Datasets

Project description:The energy required to heat, cool, and illuminate buildings continues to increase with growing urbanization, engendering a substantial global carbon footprint for the built environment. Passive modulation of the solar heat gain of buildings through the design of spectrally selective thermochromic fenestration elements holds promise for substantially alleviating energy consumed for climate control and lighting. The binary vanadium(IV) oxide VO2 manifests a robust metal-insulator transition that brings about a pronounced modulation of its near-infrared transmittance in response to thermal activation. As such, VO2 nanocrystals are potentially useful as the active elements of transparent thermochromic films and coatings. Practical applications in retrofitting existing buildings requires the design of workflows to embed thermochromic fillers within industrially viable resins. Here, we describe the dispersion of VO2 nanocrystals within a polyvinyl butyral laminate commonly used in the laminated glass industry as a result of its high optical clarity, toughness, ductility, and strong adhesion to glass. To form high-optical-clarity nanocomposite films, VO2 nanocrystals are encased in a silica shell and functionalized with 3-methacryloxypropyltrimethoxysilane, enabling excellent dispersion of the nanocrystals in PVB through the formation of siloxane linkages and miscibility of the methacrylate group with the random copolymer. Encapsulation, functionalization, and dispersion of the core-shell VO2@SiO2 nanocrystals mitigates both Mie scattering and light scattering from refractive index discontinuities. The nanocomposite laminates exhibit a 22.3% modulation of NIR transmittance with the functionalizing moiety engendering a 77% increase of visible light transmittance as compared to unfunctionalized core-shell particles. The functionalization scheme and workflow demonstrated, here, illustrates a viable approach for integrating thermochromic functionality within laminated glass used for retrofitting buildings.

Dataset Information

Acidity of Carboxylic Acid Ligands Influences the Formation of VO₂(A) and VO₂(B) Nanocrystals under Solvothermal Conditions.

Publications

Acidity of Carboxylic Acid Ligands Influences the Formation of VO<sub>2</sub>(A) and VO<sub>2</sub>(B) Nanocrystals under Solvothermal Conditions.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets