Galvanic Replacement of Semiconductor Phase I CuTCNQ Microrods with KAuBr₄ to Fabricate CuTCNQ/Au Nanocomposites with Photocatalytic Properties

Abstract

In this study, the reaction of semiconductor microrods of phase I copper 7,7,8,8-tetracyanoquinodimethane (CuTCNQ) with KAuBr(4) in acetonitrile is reported. It was found that the reaction is redox in nature and proceeds via a galvanic replacement mechanism in which the surface of CuTCNQ is replaced with metallic gold nanoparticles. Given the slight solubility of CuTCNQ in acetonitrile, two competing reactions, namely CuTCNQ dissolution and the redox reaction with KAuBr(4), were found to operate in parallel. An increase in the surface coverage of CuTCNQ microrods with gold nanoparticles occurred with an increased KAuBr(4) concentration in acetonitrile, which also inhibited CuTCNQ dissolution. The reaction progress with time was monitored using UV-visible, FT-IR, and Raman spectroscopy as well as XRD and EDX analysis, and SEM imaging. The CuTCNQ/Au nanocomposites were investigated for their photocatalytic properties, wherein the destruction of Congo red, an organic dye, by simulated solar light was found dependent on the surface coverage of gold nanoparticles on the CuTCNQ microrods. This method of decorating CuTCNQ may open the possibility of modifying this and other metal-TCNQ charge transfer complexes with a host of other metals which may have significant applications.

Long‐Range Ordered Crystals of 3D Inorganic–Organic Heterojunctions via Colloidal Lithography

“…The optical and electronic properties of semiconductors are highly dependent on the lifetime of the charge carriers . Typically, the electron/hole lifetime can be increased by either creating a heterojunction of conductor–semiconductor, semiconductor–semiconductor, and semiconductor–metal–semiconductor, or via doping of nonmetallic species in a semiconductor . In particular, inorganic–organic semiconductor heterojunctions have attracted significant attention as they combine the distinct properties of two independent classes of materials, thereby exhibiting unique optoelectronic and electrical properties suitable for various applications .…”

Galvanic Replacement of Semiconducting CuTCNQF 4 with Ag + Ions to Enhance Electron Transfer Reaction

“…Organic charge transfer complexes based on 7,7,8,8‐tetracyanoquinodimethane (TCNQ) has been a subject of intense research due to their unique properties, along with a resurgence in the interest over the past few years through the pioneering work of Dunbar et al ., Miller et al ., and Bond et al . A breadth of metal‐organic semiconducting complexes (MTCNQ) have been reported, with wide‐spread applicability in data storage,, sensors, electronic devices,,,,, catalysts, and antibacterial agents . Interestingly, the last decade has seen a rise in the use of the fluorinated analogue of TCNQ viz .…”

“…Recent work has suggested that combining MTCNQF x (x=0, 4) with metals improve the properties of the resultant hybrids than that observed for the individual components. For instance, the fabrication of metal‐MTCNQ hybrids expanded the applicability of such materials for photocatalytic and electronic applications ,,. Although the fabrication and the application of pristine MTCNQF 4 is well‐known (M=Cu or Ag), recent work has shown the importance of fabricating hybrid materials combining such organic semiconductors with metal nanoparticles .…”

“…This strategy was primarily shown for the fabrication of bimetallic colloids. Recent efforts by our group and others have expanded the use of this approach for the fabrication of M/CuTCNQ (M=Au, Pt and Pd), M/AgTCNQ (M=Au, Pt and Pd) and CuTCNQ/AgTCNQ hybrid materials ,. Although it is well‐known that the fluorinated analogue has superior properties than pristine TCNQ, the use of GR for the decoration of MTCNQF 4 with noble metals has not been intensively investigated.…”

Decorating Semiconductor Silver-Tetracyanoquinodimethane Nanowires with Silver Nanoparticles from Ionic Liquids

“…[18,19] Pearson et al reported CuTCNQ microrods decorated with gold nanoparticles via a galvanic replacement reaction in aqueous solution. [20,21] Recently, Xiao et al reported the reaction between Ag nanoparticles and TCNQ microparticles in aqueous solution which led to the formation of hybrid Ag nanoparticle-decorated AgTCNQ nanowire materials. [6] Importantly, the as-fabricated hybrid nanostructures showed good performance in non-volatile memory devices with multiple write-read-erase-read cycles in air.…”