Facile Solution Process of VO2 Film with Mesh Morphology for Enhanced Thermochromic Performance

Zhao Yu; Zhe Wang; Bin Li; Shouqin Tian; Gen Tang; Aimin Pang; Dawen Zeng; Gopinathan Sankar

doi:10.3390/ma15124129

Facile Solution Process of VO₂ Film with Mesh Morphology for Enhanced Thermochromic Performance

Materials (Basel). 2022 Jun 10;15(12):4129. doi: 10.3390/ma15124129.

Authors

Zhao Yu^{1

2}, Zhe Wang¹, Bin Li¹, Shouqin Tian¹, Gen Tang², Aimin Pang², Dawen Zeng³, Gopinathan Sankar⁴

Affiliations

¹ State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology (WUT), No. 122, Luoshi Road, Wuhan 430070, China.
² Science and Technology on Aerospace Chemical Power Laboratory, Hubei Institute of Aerospace Chemotechnology, Xiangyang 441003, China.
³ State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, No. 1037, Luoyu Road, Wuhan 430074, China.
⁴ Department of Chemistry, University College London, London WC1H0AJ, UK.

Abstract

The fabrication and applications of VO₂ film continue to be of considerable interest due to their good thermochromic performance for smart windows. However, low visible transmittance (T_lum) and solar modulation efficiency (∆T_sol) impede the application of VO₂ film, and they are difficult to improve simultaneously. Here, a facile zinc solution process was employed to control the surface structure of dense VO₂ film and the processed VO₂ film showed enhanced visible transmittance and solar modulation efficiency, which were increased by 7.5% and 9.5%, respectively, compared with unprocessed VO₂ film. This process facilitated the growth of layered basic zinc acetate (LBZA) nanosheets to form mesh morphology on the surface of VO₂ film, where LBZA nanosheets enhance the visible transmittance as an anti-reflection film. The mesh morphology also strengthened the solar modulation efficiency with small caves between nanosheets by multiplying the times of reflection. By increasing the zinc concentration from 0.05 mol/L to 0.20 mol/L, there were more LBZA nanosheets on the surface of the VO₂ film, leading to an increase in the solar/near-infrared modulation efficiency. Therefore, this work revealed the relationship between the solution process, surface structure, and optical properties, and thus can provide a new method to prepare VO₂ composite film with desirable performance for applications in smart windows.

Keywords: VO2-based composite film; solar modulation; solution process; visible transmittance.

Grants and funding

This work was supported by the National Natural Science Foundation of China (Grant No. 51772229), the 111 project (No. B18038), the National Key R&D Program of China (No. 2017YFE0192600), the Key R&D Project of Hubei Province (No.2020BAB061), the National Innovation and Entrepreneurship Training Program for College Students, Open Research Fund Program of Science and Technology on Aerospace Chemical Power Laboratory (No. STACPL220191B02), the State Key Laboratory of Materials Processing and Die & Mould Technology at Huazhong University of Science and Technology (No. P2021-010), the Open Foundation of the State Key Laboratory of Silicate Materials for Architectures at WUT (No. SYSJJ2020-04 and No. SYSJJ2021-05), and the Fundamental Research Funds for the Central Universities (No. 195201024).