Room-Temperature Synthesis of Inorganic–Organic Hybrid Coated VO₂ Nanoparticles for Enhanced Durability and Flexible Temperature-Responsive Near-Infrared Modulator Application

Abstract

Vanadium dioxide is one kind of desirable infrared modulator for sensors because of its remarkable temperature-responsive infrared modulation ability via autogeneic metal-insulator transition. However, the detriments of poor chemical stability and narrow scope of extensive-researched application (e.g., smart windows) restrict its mass production. Here, we propose a VO₂@MgF₂@PDA inorganic-organic hybrid coated architecture for greatly enhancing the optical durability more than 13 times in contrast to pristine VO₂ and the transmittance difference between room and high temperature changed within 20% (decreasing from 25 to 20.1%) at λ = 1200 nm after the ageing time of 1000 h at constant temperature (60 °C) and relative humidity (90%). Furthermore, based on the as-synthesized durability-enhanced nanoparticles, we fabricated a flexible sensor for temperature-field fluorescence imaging by integrating the VO₂-based near-infrared modulator with the upconversion fluorescence material. Additionally, the formation mechanism of VO₂@MgF₂ core-shell nanoparticles was studied in detail. The inorganic-organic combination strategy paves a new way for improving the stability of nanoparticles, and the use of VO₂-based flexible temperature-fluorescence sensors is a promising technique for remote and swift temperature-field distribution imaging on complicated and campulitropal surfaces.