Electrochromism and redox switching of cobalt hexacyanoferrate–polyaniline hybrid films in a hydrophobic ionic liquid

Flexible, Switchable Electrochromic Textiles

“…(a) WO 3 as example for cathodic electrochromism, [18][19][20][21][22][23][24][25] (b) PANI as an example for anodic electrochromism. [8][9][10][11][12][13] tungsten-containing solution. This solution was produced by dissolving tungsten powder (%0.098 mol W) in 50 mL of a 30 wt% aqueous solution of H 2 O 2 .…”

“…This behavior is termed anodic electrochromism and is typical for oxidic compounds of elements of the eighth subgroup. Further examples are complex compounds like prussian blue or polymers like polyaniline (PANI) . Figure b shows the anodic oxidation of PANI, which is accompanied by a coloring or darkening principle.…”

“…Further examples are complex compounds like prussian blue [7] or polymers like polyaniline (PANI). [8][9][10][11][12][13] Figure 2b shows the anodic oxidation of PANI, which is accompanied by a coloring or darkening principle. These electrochemical processes entail ion migration, i.e., the migration of anions or cations K þ , Figure 1b, and ion intercalation into the structure of the electrochromic compounds leading to charge equalization in the electrochemical process.…”

Multicolor electrochromic thin films and devices based on the Prussian blue family nanoparticles

“…Moreover, replacing the coordinate iron in the PB framework with other transition metals results in a distinct Prussian blue analogue (PBA) showing a different color [25]. For instance, cobalt-based PBA (Co-PBA, K 2 Co II [Fe II (CN) 6 ]) is with pale green-toreddish-brown electrochromism [26,27], and copper-based PBA (Cu-PBA, K 2 Cu II [Fe II (CN) 6 ]) shows a pale yellow-to-red color change [28,29]. Nickel-based PBA (Ni-PBA, K 2 Ni II [Fe II (CN) 6 ]) also reported showing transparent to yellow electorchromism [30].…”

Molybdate hexacyanoferrate (MoOHCF) thin film: A brownish red Prussian blue analog for electrochromic window application

“…For example, the PBAs that contains V [25,26], Fe, Ru [27], or Cr [28,29] would display the colors of green, blue or violet, respectively, by adjusting the absorption wavelength ranging from 600 nm to 800 nm. Cobalt hexacyanoferrate (CoHCF) [30,31] and nickel hexacyanoferrate (NiHCF) [32,33] optical density at a characteristic wavelength, and cycling stabilities for some known PBAs (or MHCFs) are listed in Table 1 [25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. With a wide range of color choice, high redox reversibility, and low material cost, PBAs are considered potentially for future electrochromic smart window application.…”