Pt–CeO2/reduced graphene oxide nanocomposite for the electrooxidation of formic acid and formaldehyde
The Pt–CeO2/reduced graphene oxide nanocomposite on the carbon-ceramic electrode (Pt–CeO2/RGO/CCE) was prepared by a two-step electrodeposition process. RGO was deposited on the CCE through a simple electrochemical method using graphene oxide and CCE as the precursor and electrode substrate, respectively. Then, RGO/CCE was used as a support for the Pt–CeO2 nanoparticle deposition by another electrochemical process to form the nanocomposite based electrocatalyst; Pt–CeO2/RGO/CCE. The obtained electrocatalyst was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and cyclic voltammetric techniques. The electrocatalytic activity of the Pt–CeO2/RGO/CCE toward the oxidation of formic acid and formaldehyde was investigated by cyclic voltammetry and chronoamperometry in 0.1 M H2SO4 solution. It was found that the Pt–CeO2/RGO/CCE is electrocatalytically more active than the Pt–CeO2/CCE, Pt/RGO/CCE and Pt/CCE electrocatalysts. The increased electrocatalytic efficiency of Pt in Pt–CeO2/RGO/CCE is likely to result from its combination with CeO2 to form Pt–CeO2 nanoparticles and their deposition on/in the RGO layers at the CCE surface. From the obtained results, it could be concluded that the Pt–CeO2/RGO/CCE can be used as a potential and effective electrocatalyst for direct liquid fuel cell applications.