One-Step Hydrothermal Preparation of Tungsten-Doped VO₂ particles and Durability Modification for Building Applications

Climate change has led to an increase in building energy costs, and, hence, it is vital to enhance building thermal energy efficiency. Thermochromic coatings, e.g., those based on VO₂, have great potential in this regard due to their ability to autonomously switch between absorptive and reflective states in response to cold or hot weather, respectively. However, developing a large-scale process for preparing VO₂ particles and achieving good durability in practical application are still challenging. In this work, we successfully prepared tungsten-doped VO₂ particles with a lower phase change temperature at 29.4 ^oC using a novel one-step pressure-assisted hydrothermal method, which provides a promising way for its large-scale preparation and application. In order to achieve better durability, we constructed ZnO shells for VO₂ particles, and the obtained VO₂@ZnO core-shell particles showed a better antioxidation performance. Furthermore, we designed a VO₂ coating formula with good hydrophobicity (a contact angle of 108.8^o) and adhesion with concrete by adding a certain ratio of PDMS and epoxy, endowing the coating with self-cleaning properties and application potential on building surfaces. This work proposes a high-efficiency hydrothermal preparation method for VO₂ particles and improves the durability of VO₂ coatings, providing a sustainable solution to energy-saving coatings for construction.