One pot synthesis of Pt-doped CsxWO3 with improved near infrared shielding for energy-saving film applications

In this study, Pt-doped CsxWO3 (Pt-n-CsxWO3) nanorods with improved near infrared shielding and transparent thermal insulation were synthesized by one pot solvothermal method using cheap sodium tungstate and cesium sulfate as raw materials. The role of Pt-doping on the crystal structure, morphology and transparent thermal insulation of the Pt-n-CsxWO3 products was investigated. The results indicate that Pt catalysis plays an important role in promoting oxygen vacancies and W5+ generation, and can improve the near infrared shielding performance of Pt-n-CsxWO3 greatly. Furthermore, the as-synthesized Pt-n-CsxWO3 nanorods could achieve excellent near infrared shielding and transparent thermal insulation performance without requiring additional reduction heat-treatment. Especially, when the Pt/W molar ratio is 0.01 (n = 0.01), the as -prepared Pt-0.01-CsxWO3 product with diameter of 10-30 nm and length of 20-80 nm exhibit best visible light transparency and near infrared shielding ability, with the maximum visible transmittance and near infrared shielding rate being 72% and 92% respectively. The excellent transparent thermal insulation performance of Pt-n-CsxWO3 nanoparticles without needing additional heat-treatment enables them to be more suitable for energy-saving film applications in the building and automobile window glasses.