Vertically distributed VO2 nanoplatelets on hollow spheres with enhanced thermochromic properties. Issue 29 (16th July 2018) - Xu, Huiyan
Abstract : Vanadium dioxide (VO2 ) is a phase-transition material exhibiting great potential in the field of smart windows for energy saving. Abstract : Vanadium dioxide (VO2 ) is a phase-transition material exhibiting great potential in the field of smart windows for energy saving. Herein, VO2 nanoplatelets vertically distributed on hollow spheres are synthesized via a template-free hydrothermal method. The nanoplatelets are separated and uniformly arranged on the spheres so that the dispersion and optical properties are greatly improved. Compared with the observations for the aggregated sample, visible transmittance ( T vis ) and solar modulation (Δ T sol ) improve from 33% to 50% and from 5.2% to 11.2%, respectively. Meanwhile, a large contrast transmittance of 60% at 2500 nm is obtained. T vis increases with gradual reduction in Δ T sol as the film thickness is reduced. Ultrahigh T vis of 87.2% and satisfactory Δ T sol of 5.3% are obtained. Furthermore, the as-obtained VO2 hierarchical structure exhibits higher sensitivity than VO2 nanoparticles owing to 2D-structures of nanoplatelets. This study demonstrates a promising 2D structure for promoting practical applications in smart windows.