Composites of platinum particles embedded into poly(6-cyanoindole)/poly(styrenesulfonic acid) for methanol oxidation

Poly(6-cyanoindole) (P(CnId)) is blended with poly(styrenesulfonic acid) via doping periods of 1, 10, 20, and 30 s to obtain P(CnId)–1PSS, P(CnId)–10PSS, P(CnId)–20PSS, and P(CnId)–30PSS electrodes, respectively. FT-IR studies have revealed that P(CnId) is doped with PSS. Pt particles can be doped into P(CnId)–1PSS, P(CnId)–10PSS, P(CnId)–20PSS, and P(CnId)–30PSS by chronocoulometry (0.15 C) using electrodeposition to acquire P(CnId)–1PSS–Pt, P(CnId)–10PSS–Pt, P(CnId)–20PSS–Pt, and P(CnId)–30PSS–Pt films, respectively. For comparative purposes, in this study, Pt particles were deposited into P(CnId) under the same conditions. Scanning electron microscopy (SEM) characterization revealed that platinum distributes more uniformly into the as-prepared P(CnId)–10PSS films. The anodic peak currents could be clearly observed to reach the saturation point at a methanol concentration larger than 0.8 M. A large electrocatalytic current towards methanol oxidation (27 mA cm⁻² mg⁻¹) was noticed in P(CnId)–10PSS–Pt electrodes in comparison to P(CnId)–Pt without PSS (6.3 mA cm⁻² mg⁻¹) at +0.86 V (vs. RHE), indicating that the P(CnId)–10PSS–Pt electrode reveals potential applicability as an electrocatalyst support.