Enhancement of Catalytic Activity of Reduced Graphene Oxide Via Transition Metal Doping Strategy

ABSTRACT: To compare the catalytic oxidation activities of reduced graphene oxide (rGO) and rGO samples doped with five different transition metals (TM-rGO), we determine their effects on the oxidation of L-cysteine (Cys) in aqueous solution by performing electrochemistry (EC) measurements and on the photocatalytic oxidation of Cys by using high-resolution photoemission spectroscopy (HRPES) under UV illumination. Our results show that Cr-, Fe-, and Co-doped rGO with 3+ charge states (stable oxide forms: Cr(3+), Fe(3+), and Co(3+)) exhibit enhanced catalytic activities that are due to the charge states of the doped metal ions as we compare them with Cr-, Fe-, and Co-doped rGO with 2+ charge states. GRAPHICAL ABSTRACT: The SEM images and the corresponding EC measurements for (a) Cr3+, (b) Fe3+, and (c) Co3+ doped rGO [Image: see text]