Synthesis and characterization of plate-like VO2(M)@SiO2 nanoparticles and their application to smart window

Rectangular and plate-like VO 2 (M)@SiO 2 nanoparticles were fabricated by a combination method of hydrothermal synthesis and post annealing process. Rectangular VO 2 (B) nanoplates of 20–30   nm in thickness were hydrothermally synthesized, and VO 2 (B)@SiO 2 core–shell structure was formed using a modified Stober method. Protected by inert SiO 2 shell, after post annealing the VO 2 (B)@SiO 2 was transformed to VO 2 (M)@SiO 2 without deteriorating its original plate-like morphology. Much interestingly, numerous nanopores were formed inside VO 2 (M)@SiO 2 nanoparticles due to the difference in density between VO 2 (B) and VO 2 (M), which contributes to higher optical transmittance and thermal insulation . Thermochromic foils were fabricated using the core–shell nanoparticles, showing promising potential for smart window.