Virus-templated iridium oxide–gold hybrid nanowires for electrochromic application

Abstract

A highly porous electrode comprised of biologically templated iridium oxide-gold (IrO(2)-Au) hybrid nanowires is introduced for electrochromic applications. A filamentous M13 virus is genetically engineered to display IrO(2)-binding peptides on the viral surface and used as a template for the self-assembly of IrO(2) nanoclusters into a nanowire. The open porous morphology of the prepared nanowire film facilitates ion transport. Subsequently, the redox kinetics of the IrO(2) nanowires seems to be limited by the electric resistance of the nanowire film. To increase the electron mobility in the nanowires, gold nanoparticles are chemically linked to the virus prior to the IrO(2) mineralization, forming a gold nanostring structure along the long axis of the virus. The resulting IrO(2)-Au hybrid nanowires exhibit a switching time of 35 ms for coloration and 25 ms for bleaching with a transmission change of about 30.5% at 425 nm. These values represent almost an order of magnitude faster switching responses than those of an IrO(2) nanowire film having the similar optical contrast. This work shows that genetically engineered viruses can serve as versatile templates to co-assemble multiple functional molecules, enabling control of the electrochemical properties of nanomaterials.

Design of virus-based nanomaterials for medicine, biotechnology, and energy

“…282, 509-511 In the case of TMV, mineralization can be achieved both in its interior channel 119 and around its exterior surface, 282 leading to explicit control of the width of the wires. By coupling viral particles with mineralization techniques, semiconducting, superconducting, and insulating nanowires can be formed, resulting in hybrid materials with properties of interest to energy sciences and the electronic industry.…”

Enhanced energy transport in genetically engineered excitonic networks

“…4), tobacco mosaic viruses 5,6 and the M13 virus 7 . The M13 virus has been shown to be a versatile and tunable engineering tool with a large range of applications such as batteries 8 , solar cells 9 , water splitting 10 , electrochromic devices 11 , and cancer imaging 12 . In particular, for chromophore assemblies of zinc porphyrins on the M13 virus it was proposed that both Förster resonance energy transfer (FRET) and the Dexter mechanism are involved in the transport process 7 .…”

Enhanced black state induced by spatial silver nanoparticles in an electrochromic device

“…(1) It has low optical transmittance when in the transparent state because of the inherent color and high extinction coefficient (k) of the NM materials compared with the metal ions in the electrolyte of the transparent state. [13][14][15][16][17][18] (2) The NM-ECD cannot exhibit a mirror state. Because free electrons are rarely generated in NM materials, an electric field easily penetrates the NM materials.…”

“…[8][9][10][11][12] Conventional ECDs are composed of a non-metal (NM) EC material (for example, poly(ethylene oxide), poly(methyl methacrylate), polyvinylidene difluoride, WO 3 , MoO 3 , Ir(OH) 3 , NiO). [13][14][15][16][17] In particular, WO 3 , which is the most widely known EC material, has attracted considerable attention because of its broad applications such as in ECDs, photocatalysis and sensing devices. 3 However, the use of NM-ECD encounters two drawbacks.…”