Low voltage colour modulation in hydrothermally grown Ni‐Co nanoneedles for electrochromic application

Abstract

A nanostructured film of NiCo 2 O 4 has been prepared using a hydrothermal technique by simply using separate precursors to obtain nanoneedle-like architecture for electrochromic applications. A homogeneous film consisting of packed nanoneedles with moderate density, appearing translucent white in colour, has been obtained and characterized using XRD and Raman spectroscopy techniques for confirming the composition and structure. Electrochemical analysis of the film reveals that the film shows good electrochromic properties under the anodic scan of potential with strong stability. The mechanism of the electrode under the transformation from natural white to opaque dark brown colour has been understood with the help of an in situ optical absorption spectroscopy technique. The electrode is found electrochromically active with a bias of up to 2 V and shows 50% optical contrast which makes it a good candidate for application in a solid state electrochromic device. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Induced Crystallization‐Controllable Nanoarchitectonics of 3D‐Ordered Hierarchical Macroporous Co@N‐Doped Carbon Frameworks for Enhanced Microwave Absorption

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Exploring a Redox-Active Ionic Porous Organic Polymer in Environmental Remediation and Electrochromic Application

“…However, the most interesting aspect of the viologen remains its electrochromic property as a high degree of control on its redox process can be externally achieved, and the range of colors for the viologen varies from being colorless (V 2+ ) to green/blue/purple (V ·+ ) . Therefore, a potential application of the iPOP-Bpy can be found in electrochromic devices (ECDs), a rapidly growing technology due to its various multifunctional applications, including energy saving/storage due to its capability to change optical properties when influenced by an applied bias. − To fabricate a solid-state ECD, preferably without a liquid electrolyte, proper choices of complimentary electrodes and the electrolyte are essential to obtain superior performance as measured/quantified using parameters like multicolor switching, faster switching speeds, high color contrast, and a good stability/reversibility. − In this work, the newly developed cathodic iPOP-Bpy has been used with an anodic polymeric species to design a bilayer solid-state ECD, which shows improved coloration performance, making the iPOP-Bpy molecule a potential candidate, ready to be explored in the field of solid-state ECDs.…”

Electrochromic Strategies for Modulation between Primary Colors: Covering the Visible Spectrum

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“…Parameters that quantify the performance of an ECD are switching speed, coloration or power efficiency, stability, and color coordinates, so these must have proper utilizations in applications . However, the optical output of a device is typically assessed in terms of visible colors and is considered ideal, especially for optical applications, when more than two colors can be achieved with a nominal bias manipulation …”