(515c) One-Step Non-Distructive Decoration of Transition Metal Oxide Nanoparticles on Large Scale Graphene for Electronic and Sensing Applications

Binding graphene with transition metal oxide nanoparticles(TMON) is widely used in the fields of gas sensing, electrochemical catalysis and supercapacitors. However, it is still challenging to incorporate nanoparticles on pristine graphene, since graphene is chemically inert and has no nucleation/attachment sites. Here, we show a novel and facile approach to deposit TMON (Cr₂O₃/CrO₃, MoO₃ and WO₃) on large-scale graphene by one-step photochemical reaction. The X-ray photoelectron spectroscopy shows that C≡O group is introduced after the attachment of TMON on graphene, suggesting that graphene is first functionalized based on η⁶ chemistry. Further, TMON formed in solution are attached on η⁶-functionalized graphene. Based on the Raman spectrum, the decoration of TMON with a size ranging from 20 to 50 nm leads to a blue shift in both G and 2D band, suggesting p-doping of graphene. Also, the electronic transport measurements are performed on back-gated field effect transistor. It shows that the Fermi level is moved downward by 250 mV, with Dirac point shifting to 50 V after one-step reaction. TMON@graphene on n-silicon is applied as Schottky junction solar cells, which has an enhanced power conversion efficiency due to its high erelectrical conductivity and larger work function.