Thermal-Induced Oxygen Vacancy Enhancing the Thermo-Chromic Performance of W-VO2−x@AA/PVP Nanoparticle Composite-Based Smart Windows

Jiran Liang; Tong Wu; Chengye Zhang; Yunfei Bai; Dequan Zhang; Dangyuan Lei

doi:10.3390/nano15141084

Thermal-Induced Oxygen Vacancy Enhancing the Thermo-Chromic Performance of W-VO_2−x@AA/PVP Nanoparticle Composite-Based Smart Windows

Jiran Liang^*, Tong Wu, Chengye Zhang, Yunfei Bai, Dequan Zhang, Dangyuan Lei

^*Corresponding author for this work

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

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Abstract

Tungsten-doped vanadium dioxide (W-VO₂) shows semiconductor-to-metal phase transition properties at room temperature, which is an ideal thermo-chromic smart window material. However, low visual transmittance and solar modulation limit its application in building energy saving. In this paper, a W-VO_2−x@AA core-shell nanoparticle is proposed to improve the thermo-chromic performance of W-VO₂. Oxygen vacancies were used to promote the connection of W-VO_2−x nanoparticles with L-ascorbic acid (AA) molecules. Oxygen vacancies were tuned in W-VO₂ nanoparticles by thermal annealing temperatures in vacuum, and W-VO_2−x@AA nanoparticles were synthesized by the hydrothermal method. A smart window was formed by dispersing W-VO_2−x@AA core-shell nanoparticles into PVP evenly and spin-coating them on the surface of glass. The visual transmittance of this smart window reaches up to 67%, and the solar modulation reaches up to 12.1%. This enhanced thermo-chromic performance is related to the electron density enhanced by the AA surface molecular coordination effect through W dopant and oxygen vacancies. This work provides a new strategy to enhance the thermo-chromic performance of W-VO₂ and its application in the building energy-saving field. © 2025 by the authors.

Original language	English
Article number	1084
Number of pages	14
Journal	Nanomaterials
Volume	15
Issue number	14
Online published	12 Jul 2025
DOIs	https://doi.org/10.3390/nano15141084
Publication status	Published - Jul 2025

Funding

This work was supported by the National Key R&D Program (2023YFE0203900), Tianjin Science and Technology Plan (22YFYSHZ00130), the Natural Science Foundation of Tianjin (Grant Nos. 21YDTPJC00110 and 19ZXZNGX00060), the Journal Pre-Proof Innovation and Technology Commission of Hong Kong through a Mainland–Hong Kong Joint Funding Scheme (Grant MHP/162/22).

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 7 Affordable and Clean Energy

Research Keywords

AA
oxygen vacancy
smart windows
W-VO2

Publisher's Copyright Statement

This full text is made available under CC-BY 4.0. https://creativecommons.org/licenses/by/4.0/

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title = "Thermal-Induced Oxygen Vacancy Enhancing the Thermo-Chromic Performance of W-VO2−x@AA/PVP Nanoparticle Composite-Based Smart Windows",

abstract = "Tungsten-doped vanadium dioxide (W-VO2) shows semiconductor-to-metal phase transition properties at room temperature, which is an ideal thermo-chromic smart window material. However, low visual transmittance and solar modulation limit its application in building energy saving. In this paper, a W-VO2−x@AA core-shell nanoparticle is proposed to improve the thermo-chromic performance of W-VO2. Oxygen vacancies were used to promote the connection of W-VO2−x nanoparticles with L-ascorbic acid (AA) molecules. Oxygen vacancies were tuned in W-VO2 nanoparticles by thermal annealing temperatures in vacuum, and W-VO2−x@AA nanoparticles were synthesized by the hydrothermal method. A smart window was formed by dispersing W-VO2−x@AA core-shell nanoparticles into PVP evenly and spin-coating them on the surface of glass. The visual transmittance of this smart window reaches up to 67%, and the solar modulation reaches up to 12.1%. This enhanced thermo-chromic performance is related to the electron density enhanced by the AA surface molecular coordination effect through W dopant and oxygen vacancies. This work provides a new strategy to enhance the thermo-chromic performance of W-VO2 and its application in the building energy-saving field. {\textcopyright} 2025 by the authors.",

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AU - Zhang, Dequan

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N2 - Tungsten-doped vanadium dioxide (W-VO2) shows semiconductor-to-metal phase transition properties at room temperature, which is an ideal thermo-chromic smart window material. However, low visual transmittance and solar modulation limit its application in building energy saving. In this paper, a W-VO2−x@AA core-shell nanoparticle is proposed to improve the thermo-chromic performance of W-VO2. Oxygen vacancies were used to promote the connection of W-VO2−x nanoparticles with L-ascorbic acid (AA) molecules. Oxygen vacancies were tuned in W-VO2 nanoparticles by thermal annealing temperatures in vacuum, and W-VO2−x@AA nanoparticles were synthesized by the hydrothermal method. A smart window was formed by dispersing W-VO2−x@AA core-shell nanoparticles into PVP evenly and spin-coating them on the surface of glass. The visual transmittance of this smart window reaches up to 67%, and the solar modulation reaches up to 12.1%. This enhanced thermo-chromic performance is related to the electron density enhanced by the AA surface molecular coordination effect through W dopant and oxygen vacancies. This work provides a new strategy to enhance the thermo-chromic performance of W-VO2 and its application in the building energy-saving field. © 2025 by the authors.

AB - Tungsten-doped vanadium dioxide (W-VO2) shows semiconductor-to-metal phase transition properties at room temperature, which is an ideal thermo-chromic smart window material. However, low visual transmittance and solar modulation limit its application in building energy saving. In this paper, a W-VO2−x@AA core-shell nanoparticle is proposed to improve the thermo-chromic performance of W-VO2. Oxygen vacancies were used to promote the connection of W-VO2−x nanoparticles with L-ascorbic acid (AA) molecules. Oxygen vacancies were tuned in W-VO2 nanoparticles by thermal annealing temperatures in vacuum, and W-VO2−x@AA nanoparticles were synthesized by the hydrothermal method. A smart window was formed by dispersing W-VO2−x@AA core-shell nanoparticles into PVP evenly and spin-coating them on the surface of glass. The visual transmittance of this smart window reaches up to 67%, and the solar modulation reaches up to 12.1%. This enhanced thermo-chromic performance is related to the electron density enhanced by the AA surface molecular coordination effect through W dopant and oxygen vacancies. This work provides a new strategy to enhance the thermo-chromic performance of W-VO2 and its application in the building energy-saving field. © 2025 by the authors.

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