A novel multifunctional composite based on reduced graphene oxide, poly-o-phenylenediamine and silicotungstic acid

Comparison of electrochemical behavior of composites based on graphene oxide, poly‐o‐phenylenediamine, and heteropolyacids

“…Figure 2 represents CVA curves for synthesis of composites on SPCE + GO (inserts on the right in each of the figures A–C). To produce a SiW composite (sample No 002, Figure 2А), polymerization was carried out in 10 −2 М OPD + 10 −3 М SiW solution in 1 М H 2 SO 4 at the scan rate 50 mV/s in a narrow potential range (−500 to +450 mV) since GO is actually a catalyst for PPD polymerization (at the same time reducing to the RGO) 17,18 and the synthesis begins far prior to achieving the potential of 1.2 V, at which the synthesis is carried out in the absence of GO. Similarly, sample No 010 was obtained.…”

“…Earlier, 17,18,33 we studied in sufficient details the catalytic properties of composites like No 002 (RGO‐PPD‐SiW) for the exemplary quinone‐hydroquinone and ferro‐ferricyanide redox transitions. In these works, the comparison of CVA for unmodified and RGO‐PPD‐SiW‐modified SPCE demonstrated that the presence of the composite on the electrode surface enhances the reaction reversibility.…”

“…Recently we started studying novel multifunctional composites based on RGO, EAP, and POM 17,18 . We use heteropolyacids (HPA) as POM.…”

“…The presence of various oxygen‐containing groups on nanosheet edges in acid medium promotes to formation of hydrogen bonds with protonated nitrogen atoms in PPD; furthermore, the conjugated bonds in GO allow binding individual polymer units by π‐stacking. We have shown that interaction of GO and the OPD results in a redox reaction in which GO is reduced to the RGO, and OPD begins to oxidize and polymerize 17,18 . We studied a novel composite on a planar screen‐printed carbon electrode (SPCE) as a three‐electrode electrochemical cell.…”

“…For example of quinone‐hydroquinone and ferro‐ferricyanide, it was demonstrated that the composite exhibits electrocatalytic properties in the same potential range. Use of SPCE allows treating the suggested electrochemical system as a model for sensors based on RGO‐PPD‐SiW 17,18 …”