Ammonia induced strong LSPR effect of chain-like ATO nanocrystals for hyperspectral selective energy-saving window applications

Sb-doped SnO2 (ATO) is a promising multifunctional material with great potentials for practice applications, however, it suffers from poor absorption efficiency of near-infrared (NIR) light due to its relatively weak localized surface plasmon resonance (LSPR) effect. In this study, a series of chain-like ATO nanocrystals (NCs) with high Sb5+/Sb3+ ratio(s) and oxygen defect concentration were precisely prepared by a simple but efficient precipitation-hydrothermal method. The introduction of NH3 served as a double-hero in controlling both the solution pH and the shape of nanocrystals. Both experimental and theoretical calculation results have indicated that our synthesis strategy effectively increases the free carrier concentration and mobility of ATO NCs to improve LSPR effect, and thereby effectively broaden the NIR light absorption region and improve the absorption capacity. Furthermore, the as-prepared ATO hydrosols show great potentials for practical applications in energy-saving building since a flexible application mode as an energy-saving window can be implemented. Both the formation of ATO hydrosol windows by pouring into the laminated glass and spin-coating onto the flat glass to create ATO coatings can result in excellent optical properties and thermal insulation performance. These findings may not only accelerate the commercialization process of ATO but also provide valuable theoretical guidance for developing novel hyperspectral materials.