Series of M_xWO₃/ZnO (M = K, Rb, NH₄) nanocomposites: Combination of energy saving and environmental decontamination functions

Series of new M_xWO₃/ZnO (M = K, Rb, NH₄) nanocomposites were successfully prepared by simple two-steps method in a mild condition. The as-prepared M_xWO₃/ZnO composite films showed nice UV light blocking, VIS light transmittance and NIR light shielding properties. Furthermore, the optical properties of the composites could be tuned by adjusting the M_xWO₃ content and film thickness. Particularly, the Rb_xWO₃/ZnO with small amounts of Rb_xWO₃ contents exhibited the promising optical properties and also excellent thermal stability. From the practical application viewpoint, the simulated experiment found that the simulated house decorated with sample film as smart window presented nice NIR light induced heat insulation for energy saving, and the Rb_xWO₃/ZnO decorated one was even better than that of ITO. In addition, both the powder and film samples displayed high continuously toxic NO gas decomposing ability under the UV light irradiation. The mechanisms for the multifunctionality of the samples were related to the polaron transition, localized surface plasma resonance (LSPR) and suitable band gaps. Therefore, the new M_xWO₃/ZnO composites and relevant films not only showed promising harmful UV light absorption, high VIS light brightness, excellent NIR light induced heat insulation, but also nice toxic NO gas photodecomposition property, indicating their brilliant prospect in both of energy saving and environmental cleanup.