Unusual attempt to direct the growth of bimetallic Ag[at]Pt nanorods on electrochemically reduced graphene oxide nanosheets by electroless exchange of Cu by Pt for an efficient alcohol oxidation

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology 2017-01, Vol.19 (1), p.1-13
• Main Authors: Jeena, SE, Gnanaprakasam, P, Selvaraju, T
• Format: Article
• Language: English
• Subjects: Anodizing; Bimetals; Electrodes; Ethanol; Ethyl alcohol; Graphene; Nanostructure; Oxidation
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-016-3643-3

A simple and an efficient tool for the direct growth of bimetallic Ag[at]Pt nanorods (NRDs) on electrochemically reduced graphene oxide (ERGO) nanosheets was developed at glassy carbon electrode (GCE). Initially, Cu shell was grown on Ag core as Ag[at]Cu NRD by the seed-mediated growth method. Accordingly, Cu shell has been successfully replaced by Pt using the electroless galvanic replacement method with ease by effective functionalization of L-tryptophan on ERGO surface (L-ERGO), which eventually plays an important role in the direct growth of one-dimensional bimetallic NRDs. As a result, the synthesized Ag[at]Pt NRD-supported L-ERGO nanosheets (Ag[at]Pt NRDs/L-ERGO/GCE) were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDAX) and Raman spectroscopy. Anodic stripping voltammetry was used to explore its electrochemical properties. Finally, the developed bimetallic Ag[at]Pt NRDs/L-ERGO/GCEs were studied as a better electrocatalyst compared to the commercial catalysts such as Pt sub(40)/C or Pt sub(20)/C-loaded electrode for the oxidation of ethanol or methanol with a high tolerance level and an enhanced current density. In addition, the long-term stability was studied using chronoamperometry for 1000 s at the bimetallic NRD electrode for alcohol oxidation which impedes the fouling properties. The unfavourable and favourable electrooxidation of ethanol at Ag[at]Cu NRDs/L-ERGO/GCE (a) and Ag[at]Pt NRDs/L-ERGO/GCE (b) is discussed. The synergistic effect of Ag core and catalytic properties of Pt shell at Ag[at]Pt NRDs/L-ERGO/GCE tend to strongly minimize the CO poisoning effect and enhanced ethanol electrooxidation.