Assembly, electrochemical characterisation and electrocatalytic ability of multilayer films based on [Fe(bpy)3]2+, and the Dawson heteropolyanion, [P2W18O62]6−

Abstract

Abstractimmobilise up to thirty monolayers, with the system exhibiting well behaved redox behaviour. The stability of the assembly towards redox switching was investigated, with it being found be extremely stable once the outer layer is anionic in nature. The 2 immobilised film was also tested for electrocatalytic activity for the reduction of nitrite, hydrogen peroxide and bromate, and was shown to be an efficient electrocatalyst.

Hybrid materials utilizing polyelectrolyte-derivatized carbon nanotubes and vanadium-mixed addenda heteropolytungstate for efficient electrochemical charging and electrocatalysis

“…It was found that an addition of diethyl ether to the ink suspension caused an increase (approximately by 50 %) of the current densities associated with all the observed redox processes of the CNTs/PDDA/[P 2 This could be ascribed to the formation of the CNT surface groups enhanced or activated by diethyl ether. Our recent studies also showed that an increase of the current intensities was also seen when the ink suspension was prepared using CNTs that had already been modified with PDDA and [P 2 W 17 VO 62 ] 8− .…”

“…We found that the investigated system exhibited lower stability in more alkaline media: The percentage losses of activities were up to 30 and 20 % at pH 4.5 and 7.0, respectively. This could be linked to the pH-dependent nature of the polytungstate reduction processes: In alkaline media, availability of protons which are needed to accompany the reductions is obviously lower relative to that in 0.5 mol dm −3 H 2 SO 4 [2].…”

“…Their electrochemical properties such as high stability and conductivity, as well as ability to undergo reversible multiple electron transfer redox processes, make them promising materials to construct electrode materials of electrochemical applications in various areas such as electrocatalysis [2], electrochromic and photochromic devices [3,4], corrosion protection [5], ion-selective membranes [6], or electrochemical capacitors [7]. There are two principal types of polyoxometalates structures, namely Keggin ([XM 12 type, where X is the non-metallic element such as P, Si, and As while M is a metal redox center, usually W (VI) , Mo (V) , V (V) , Nb (V) , or Ta (V) [1].…”

“…A high anionic charge of POM layers or adsorbates permits their application as linking agents during fabrication of three-dimensional network films consisted of anionic and cationic species interconnected via simple electrostatic interactions. This layer-by-layer concept was applied to the formation of POM-based hybrid films containing conducting polymers [20][21][22][23], positively charged organics like poly(vinylpyridine) or poly(ethylenimine) [24] and transition metal (Fe, Ru, Os, Cu) complexes [2,[25][26][27].…”

Electrocatalysis by crown-type polyoxometalates multi-substituted by transition metal ions; Comparative study

“…The probe can undergo the redox transformation at the underlying electrode surface after diffusion through the multilayer system or within the film by electron transfer mediated by the redox sites within the LBL film [28]. …”