Au-Pt bimetallic nanoparticles anchored on conducting polymer: An effective electrocatalyst for direct electrooxidation of sodium borohydride in alkaline solution

This work proposes Au-Pt nanoparticles decorated poly(p-aminophenol) (PAP) film on a glassy carbon electrode for direct electrochemical oxidation of sodium borohydride. The Au-Pt bimetallic surfaces were prepared with two electrodeposition procedures which are the simultaneous electro-deposition (1-Au-Pt/PAP/GCE) and the successive electro-deposition (2-Au-Pt/PAP/GCE) procedures. The catalysts were used for the investigation of borohydride electrochemical oxidation and compared catalytic activities by CV, RDEs and chronoamperometric techniques. AFM, SEM, XPS, XRD and CV were used to identify of the structural and morphological properties of the developed modified surfaces. The results of electrochemical measurements indicated that simultaneous electro-deposition of Au-Pt to the polymer structure significantly shifted negative oxidation potential and increases the current density of borohydride electrochemical oxidation. The exchange electron number of 1-Au-Pt/PAP/GC and 2-Au-Pt/PAP/GC electrodes were calculated as 7.8 and 6.7, respectively. This approves the strong tendency of the 1-Au-Pt/PAP catalyst toward effective direct electrochemical oxidation of NaBH4 in an alkaline medium.