In situ synthesis of highly dispersed VO2(M) nanoparticles on glass surface for energy efficient smart windows

Thermochromic VO₂-based smart windows are considered as a highly promising building envelope to reduce building energy consumption. However, the inherent unsatisfactory optical performance hindered its practical applications and nanocomposite films are testified to be the most promising strategy addressing this issue, while uniformly dispersing nanoparticles is often a challenge. Herein, a facile in situ method was proposed to directly fabricate highly dispersed VO₂ nanoparticles (HD-VN) on a glass surface from the VOC₂O₄·xH₂O aqueous solution to achieve the high-optical performance VO₂ film (HD-VN film). The forming mechanism of HD-VN was fully elucidated and HD-VN was generated via the sintering process from the irregular VO₂ particles derived from the decomposition of polyvinyl pyrrolidone (PVP). The HD-VN film showed excellent luminous transmittance (T_lum) of 72.5% and solar energy modulation efficiency (ΔT_sol) of 10.1%, the former was attributed to the reduced refractive index which led to a reduced reflectance of HD-VN film, and the latter was ascribed to the localized surface plasmon resonance (LSPR) behavior of the HD-VN. The simple and cost-efficient synthesis strategy would promote the application of VO₂ film in energy-efficient glazing, and also shed light on the structures’ design applied to the field of optics, catalysts, and sensors.