High performance visible and near-infrared region electrochromic smart windows based on the different structures of polyoxometalates

Reflective Structural Color Tunability of Inorganic Electrochromic Devices by Interferometric Modulation

In the multicolor regulation of visible-light band, the inorganic electrochromic multicolor modulation has always been the bottleneck of expanding the application of inorganic electrochromic reflection display. An electrochromic device (ECD) based on an ultracompact unsymmetric Fabry–Perot resonator was designed. Electrochromic oxides such as tungsten oxide, offer the possibility to tune their refractive index and extinction coefficient upon ion insertion, allowing active control over resonance conditions for Fabry–Perot cavity-type devices. The spectrum colors of red, yellow, green and blue can be obtained by adjusting the thickness of tungsten oxide in the W/(WO[Formula: see text]H2O) electrode. The optical constants of tungsten oxide can be adjusted reversibly by using electrochemical ion insertion/stripping, and the reflection peak of W/(WO[Formula: see text]H2O) electrode in the visible-light band can be adjusted. The dynamic color control of the ECDs can be achieved finely.

The effect of electrolytes on the electrochromic performance of nickel-substituted tungstophosphate and TiO2 nanowire composite films

A film based on POM and TiO₂ nanowires in Li⁺-based media displays enhanced electrochromic performance compared to that in H⁺-based electrolyte.

Polyoxometalates on Functional Substrates: Concepts, Synergies, and Future Perspectives

Polyoxometalates (POMs) are molecular metal oxide clusters that feature a broad range of structures and functionalities, making them one of the most versatile classes of inorganic molecular materials. They have attracted widespread attention in homogeneous catalysis. Due to the challenges associated with their aggregation, precipitation, and degradation under operational conditions and to extend their scope of applications, various strategies of depositing POMs on heterogeneous substrates have been developed. Recent ground-breaking developments in the materials chemistry of supported POM composites are summarized and links between molecular-level understanding of POM-support interactions and macroscopic effects including new or optimized reactivities, improved stability, and novel function are established. Current limitations and future challenges in studying these complex composite materials are highlighted, and cutting-edge experimental and theoretical methods that will lead to an improved understanding of synergisms between POM and support material from the molecular through to the nano- and micrometer level are discussed. Future development in this fast-moving field is explored and emerging fields of research in POM heterogenization are identified.

Supramolecular strategy for smart windows

Supramolecular strategy-based materials are outlined and their applications for fabricating smart windows are summarized for future exploration of ideal smart windows.

Highly Efficient, Near-Infrared and Visible Light Modulated Electrochromic Devices Based on Polyoxometalates and W18O49 Nanowires

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, K₂₈Li₅H₇P₈W₄₈O₁₈₄·92H₂O (P₈W₄₈), and W₁₈O₄₉ nanowires. Unlike most reported electrochromic smart devices, the resulting P₈W₄₈ and W₁₈O₄₉ 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 P₈W₄₈ and W₁₈O₄₉ and precise structural control over the nanocomposites, the prepared electrochromic smart devices exhibit high efficiency, quick response and excellent stability.

Vanadium substituted Keggin-type POM-based electrochromic films showing high performance in a Li+-based neutral non-aqueous electrolyte

Vanadium substituted Keggin type POM-based electrochromic films show high performance in LiClO₄-based non-aqueous electrolyte. The use of the neutral non-aqueous electrolyte makes it easy to fabricate a device.

Immobilized polyazomethines containing triphenylamine groups on ITO: synthesis and acidochromic, electrochemical, electrochromic and photoelectronic properties

A new series of polyazomethines (PAMs) containing triphenylamine (TPA) as easily-oxidized units were synthesized as highly soluble materials with electrochromism.

Patternable PEDOT nanofilms with grid electrodes for transparent electrochromic devices targeting thermal camouflage

This paper reports a new type of transmitting mode electrochromic device that uses the high-contrast electrochromism of poly(3,4-ethylenedioxythiophene) (PEDOT) and operates at long-wavelength infrared (8-12 μm) . To maximize the transmittance contrast and transmittance contrast ratio of the device for thermal camouflage, we control the thickness of the thin PEDOT layer from 25 nm to 400 nm and develop a design of grid-type counter electrodes. The cyclability can be greatly improved by selective deposition of the PEDOT film on grid electrodes as an ion storage layer without any loss of overall transmittance. The device with optimized architectures shows a high transmittance contrast ratio of 83 % at a wavelength of 10 μm with a response rate under 1.4 s when alternating voltage is applied. Captured images of an LED lamp behind the device prove the possibility of active, film-type camouflage against thermal detection.

Enhanced electrochromic properties of a polypyrrole–indigo carmine–gold nanoparticles nanocomposite

Enhanced electrochromic properties of a PPy–IC–Au_nanop nanocomposite obtained by the one-step growth of gold nanoparticles and electropolymerization of indigo carmine doped polypyrrole.