Synthesis of Sb-doped SnO2 (ATO) hollow microspheres and its application in photo-thermal shielding coating

ATO hollow microspheres were synthesized with carbon ball template by the hydrothermal method. In order to study the likely formation mechanism of ATO hollow microspheres, the morphology, crystalline structure and microstructure were examined with XRD, SEM, EDS and HRTEM. The optical and thermal characteristics of the microspheres including absorption and reflectance, and thermal conductivity, infrared emissivity (8 similar to 14 mu m), and specific heat capacity were also measured. Silicone acrylic emulsion coating containing different dosages of ATO microspheres were then prepared, and their Vis-NIR transmittance and photo-thermal shielding performance were studied. Compared to solid microspheres, ATO hollow microspheres showed higher absorption, lower reflectance, lower thermal conductivity, higher specific heat capacity and higher infrared emissivity. Results also showed that ATO hollow microspheres introduction reduced the Vis-NIR transmittance of the silicone acrylic emulsion coating, and also enhanced the photo-thermal shielding performance of coating by higher absorption, slower thermal conduction and radiative cooling. This study indicates that coating containing ATO hollow microspheres is a promising material that can be applied for energy conservation.