In-situ growth of Cs0·33WO3@ATO composite material with enhanced NIR shielding rate for energy-saving coating

Abstract

Driven by the global goal of “carbon neutrality”, energy conservation, emission reduction and low-carbon development have become important research directions. Transparent thermal insulation materials can effectively shield near-infrared radiation while maintaining high visible light transmittance, making them widely applicable in building energy conservation. In this paper, antimony-doped tin oxide (ATO) and cesium tungsten bronze (CsxWO3, or CWO) are chosen to be composited in order to solve the problems of the poor shielding effect of ATO for short-wavelength near-infrared (NIR) light and the unsatisfactory shielding effect of CWO for long-wavelength NIR light. Therefore, in this study, we employed a one-step hydrothermal method to form a novel CWO@ATO core-shell structure to combine the advantages of both ATO and CWO. By adjusting the composite ratio of ATO and CWO, both the physical and electronic stucutres are effectively tuned to promote the optical modulation in a broad bandwidth. Enventually, the core-shell structured composite exhibit an excellent near-infrared blocking property, surpassing the pure ATO by 27.8 % in the wavelength region of 780∼1500 nm while improving by 14.9 % compared to CWO in the long wavelength between 1500 and 2500 nm. Furthermore, the prepared CWO@ATO core-shell structure repesents near-infrared shielding rate as high as 93.1 % in the full NIR spectrum, and possesses an overall thermal insulation coefficiency (THI) of 9.33 in the full range from 780 nm to 2500 nm, which is substantially larger than that of pure ATO and CWO by a factor of 2.37 and 3.05, respectively. This core-shell structure engineering realizes the utilization of complementary advantages of ATO and Cs0·33WO3 materials, providing a new method to improve the near-infrared performance of energy-saving glass coating, and having broad application prospects in the field of low-carbon buildings.