A Facile Preparation of Titanium Dioxide-Iron Oxide@Silicon Dioxide Incorporated Reduced Graphene Oxide Nanohybrid for Electrooxidation of Methanol in Alkaline Medium

An iron oxide-silicon dioxide coated titanium dioxide (TiO₂-Fe₂O₃@SiO₂) incorporated reduced graphene oxide (rGO) nanohybrid was prepared by a simple hydrothermal method using titanium tetraisopropoxide (TTIP) and graphite flakes as the precursors. Tetraethoxysilane (TEOS) was used to form a SiO₂ coating on Fe₂O₃ nanoparticle surface (Fe₂O₃@SiO₂). The presence of SiO₂ layer would facilitate the formation of Fe₂O₃ on the TiO₂ surface by an electrostatic attraction that led to the formation of TiO₂-Fe₂O₃@SiO₂. The transmission electron microscopy (TEM) results revealed the successful attachment of Fe₂O₃@SiO₂ particles to the TiO₂ surface and a uniform distribution of TiO₂-Fe₂O₃@SiO₂ composites on the rGO sheet. Furthermore, the rGO/TiO₂-Fe₂O₃@SiO₂ nanohybrid modified platinum (Pt) electrode was used for the electrocatalytic oxidation of methanol in alkaline medium. The rGO/TiO₂-Fe₂O₃@SiO₂ nanohybrid with weight ratio of 1:3:1 (rGO:TiO₂:Fe₂O₃) showed a higher electrocatalytic activity toward methanol oxidation with an anodic peak current density of 2.45 mA/cm². Moreover, the nanohybrid displayed a higher stability with 91.58% retention of the initial current density after 5000 s in long term current-time curve. This newly prepared rGO/TiO₂-Fe₂O₃@SiO₂ nanohybrid could be a promising anodic catalyst for the direct methanol fuel cells (DMFCs) application.