화학공학소재연구정보센터
International Journal of Hydrogen Energy, Vol.42, No.25, 16258-16268, 2017
Highly efficient, large surface area and spherically shaped Pt particles deposited electrolytically synthesized graphene for methanol oxidation with impedance spectroscopy
Graphene was synthesized via electrochemical exfoliation technique of graphite rod in Poly (sodium 4-styrenesulfonate) solution. Laser Raman and X-ray Diffraction Spectroscopies were used to confirm the defects and crystal nature of graphene. The surface wettability studies based on water contact angle, further differentiates the affinity of as prepared graphene and pristine graphite towards water. Modified Glassy carbon (GC) electrodes were prepared by electro-deposition of Platinum (Pt) on bare and graphene coated GC, denoted as GC/Pt and graphene/Pt modified GC respectively. The morphology and chemical composition of the thus synthesized graphene and graphene/Pt modified electrodes were investigated by High resolution transmission electron microscopy, Scanning electron microscopy and Energy dispersive spectroscopy. The electrochemically active surface area of the electro-deposited spherically shaped Pt particles was calculated to be 63.96 m(2) g(-1) and 25.10 m(2) g(-1) on graphene/Pt and GC/Pt, respectively. The electrocatalytic performance of modified electrodes for methanol oxidation was envisaged by cyclic voltammetry, linear sweep voltammetry and chronoamperometry. Graphene/Pt modified GC electrode showed higher oxidation peak current (42.90 mA cm(-2)) than GC/Pt modified electrode (16.24 mA cm(-2)) in forward scan of methanol oxidation because of the uniform distribution of spherically shaped Pt particles on graphene. The reaction path for methanol oxidation at different potentials was elucidated by means of Electrochemical Impedance Spectroscopy. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.