All-in-one display device with multicolor states derived from NBU-3 MOF/monoalkylated viologen hybrid ionogel material

Abstract Recently, metal-organic frameworks (MOFs) have gained considerable attention for electrochromic (EC) applications owing to their improved electrochemical performance and superior processing ability. As a class of well-recognized organic EC materials, viologens are desirable and they are major active EC components for most of the marketed EC devices due to their structural versatility and property tunability. Over the past two decades, extensive efforts have been made to design and synthesize different types of viologen-based materials with enhanced EC properties. Herein, we report fabrication of MOFs and 1-hexyl-[4,4′-bipyridin]-1-ium bis (trifluoromethane sulfonyl) imide [MHV][TFSI] based all-in-one hybrid ionogel as an electrochromic device (ECD). The fabricated ECD showed reversible multicolor property with stability over 2000 cycles. Initially, the ECD showed light yellow color, and subsequently, it changed to light green, blue, and maroon color accordingly. The fabricated ECD displayed fast coloration time(tc), and bleaching times(tb) of 4.35 s and 7.72 s, respectively, along with a coloration efficiency of 99.14 cm2/C. The performance enhancement mechanisms are also concisely discussed in the present work. This work introduces the novel way to fabricate MOF based electrochromic ionogel (ECIG) ECDs and paves the way to the advancement of electrochromic ionogel-based display devices.