Enhancing NIR Shielding Properties of Au/CsWO₃ Composite via Physical Mixing and Solvothermal Processes

Abstract

This research aims to enhance the near-infrared (NIR) shielding ability of cesium tungsten bronze (CsWO3) by increasing the spectral absorption in this region through the incorporation of gold nanorods (AuNR). Two approaches were used to prepare the composite materials: physical mixing and solvothermal process. The effects of gold nanorods content on the crystalline size, particle size, shape, and optical properties of the composite were investigated systematically using DLS, TEM, XRD, and UV–Vis spectroscopy techniques, respectively. The physical mixing process synergizes AuNR and CsWO3 into a composite which has better NIR absorption than that of neat AuNR and CsWO3 nanorods. A composite with 10 mol% of AuNR shows the highest NIR absorption ability due to the surface plasmon resonance and energy coupling between Au and CsWO3. With the solvothermal process, the CsWO3 nanorods grow up to 4–7 microns when the AuNR content increases to 0.8 mol% due to the incorporation of the Au atoms. The microsized CsWO3 rods have superior NIR shielding property compared to other conditions, including the AuNR+CsWO3 nanocomposite with 10 mol% of AuNR from the physical mixing process.

Keywords

• gold/CsWO₃ nanorods
• composites
• NIR shielding
• plasmonic coupling
• localized plasmon resonance