Highly Efficient, Near-Infrared and Visible Light Modulated Electrochromic Devices Based on Polyoxometalates and W₁₈O₄₉Nanowires

Over the past years the performance of electrochromic smart windows with the promising potential for significant energy savings has been progressively improved; however, the electrochromic windows have not yet to come into use at scale mainly because the electrochromic materials suffer from some significant drawbacks such as low coloration efficiency, slow switching time, bad durability and poor functionality. Herein, we fabricate the optically modulated electrochromic smart devices through sequential deposition of the crown-type polyoxometalates, K 28 Li 5 H 7 P 8 W 48 O 184 ·92H 2 O (P 8 W 48 ), and W 18 O 49 nanowires. Unlike most reported electrochromic smart devices, the resulting P 8 W 48 and W 18 O 49 nanocomposites allow active and selective manipulation of the transmittance of near-infrared (750–1360 nm) and visible light (400–750 nm) by varying the applied potential. Furthermore, thanks to the stable nature of both P 8 W 48 and W 18 O 49 and precise structural control over the nanocomposites, the prepared electrochromic smart devices exhibit high efficiency, quick response and excellent stability.