In this study, a well-controlled interfacial engineering method for the synthesis of SiO /TiO /VO three-layered hollow nanospheres (TLHNs) and TLHNs-based multifunctional coatings is reported. The as-prepared coatings allow for an outstanding integration of thermochromism from the outer VO (M) layer, photocatalytic self-cleaning capability from the middle TiO (A) layer, and antireflective property from internal SiO HNs. The TLHNs coatings exhibit excellent optical performance with ultrahigh luminous transmittance (T = 74%) and an improved solar modulation ability (ΔT = 12%). To the best knowledge, this integrated optical performance is the highest ever reported for TiO /VO -based thermochromic coatings. An ingenious computation model is proposed, which allows the n of nanostructured coatings to be rapidly obtained. The experimental and calculated results reveal that the unique three-layered structure significantly reduces the refractive index (from 2.25 to 1.33 at 600 nm) and reflectance (Rave, from 22.3 to 5.3%) in the visible region as compared with dense coatings. Infrared thermal imaging characterization and self-cleaning tests provide valid evidence of SiO /TiO /VO TLHNs coatings' potential for energy-saving and self-cleaning smart windows. The exciting inexpensive and universal fabrication process for well-defined structures may inspire various developments in processable and multifunctional devices.

No abstract

No abstract

Thermochromic vanadium dioxide (VO 2 ) as one of the most promising candidates for smart windows has attracted widespread attention in recent years. Excellent optical performances (luminous transmittance, T lum , and solar modulation efficiency, ΔT sol ) of VO 2 -based coatings are usually pursued as crucial issues. In the current work, we report an ingenious approach for the synthesis of VO 2 @SiO 2 dual-shell hollow nanospheres (DSHNs) and the preparation of DSHNs thermochromic coatings. A sequential bifunctional template-induced mechanism for the formation of DSHNs was proposed. Because of the unique hollow-core and dualshell structure, the as-prepared VO 2 @SiO 2 DSHNs coatings exhibited appealing optical performances with enhanced luminous transmittance of 61.8% and solar modulation efficiency of 12.6%, compared with continuous and dense VO 2 coatings. It has been proved that the improvement of visible transmittance could be ascribed to the effective reduction of refractive index (from 2.6 to 1.6 at 630 nm). In addition, its excellent thermochromic performance has been confirmed by the model cubes measurements, expressing a great potential as energy-efficient smart windows in high-rise buildings. The bifunctional template-induced synthetic strategy may inspire more facile, efficient and inexpensive processes for development of well-defined multishelled hollow nanostructures for varied applications.