Controllable Design of Bifunctional VO<sub>2</sub> Coatings with Superhydrophobic and Thermochromic Performances
Rui Sun, Binbin Jin, Lin Yao, Yiman Liu, Jing Li, Jie Liang, Junhui He
Abstract
The structure and functions of natural organisms provide great inspirational sources for designing and manufacturing bionic coatings, which hold a distinguished scientific promise to tackle challenges facing humans. In this work, we report a facile and controllable approach to prepare various hexagonal periodic array VO2 thin films by simply manipulating the speed of the dip-coating operation. The hexagonal cellular-structured VO2 surface delivered the best thermochromic performance with a Tlum of 79.34% and a ΔTsol of 9.87%. Impressively, superhydrophobic and thermochromic properties could be integrated into hexagonal semi-dome thin films (with a Tlum of 70.9%, a ΔTsol of 9.3%, and a water contact angle of 150°) without any post-treatment by low-surface-energy chemicals, which hold considerable potential for application in multifunctional smart windows. Moreover, based on the Cassie–Baxter mode and finite-difference time-domain calculations, the dependence of the thermochromic and wettability performances on the VO2 structure has been investigated in this study.