Synthesis of Nanostructured Graphene-Cobalt Manganese Oxide Hybrids for Electrochemical Catalysis Applications

• Main Authors: Wen-Jie Lan, 藍文婕
• Other Authors: Chun-hu Chen
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/13232813741654745773

碩士 === 國立中山大學 === 化學系研究所 === 102 === A simple redox reaction was successfully conducted for the controlled synthesis of 3D flower-like cobalt manganese oxides (CMO) accompanied by unique Y-shaped subunits with a homogeneous elemental distribution and mixed-valence features. This reaction is attributed to the highly conductive and reductive properties of electrochemical catalysis for sensing hydrogen peroxide and oxygen reduction reactions (ORR). The diameters and the nanoflakes of the CMO spheres increased in size with a prolonged reaction time and increased temperatures. In addition, the nanowire impurities were obtained with a reaction temperature of 200oC for 24 hours. The results indicate that there are two different growth paths that are dependent on the reaction temperatures. Graphene with high conductivities and surface areas was used to generate 3D flower-like graphene-cobalt manganese oxide composites (G-CMO) for optimal H2O2 and ORR performance. First, the surface of the CMO materials was modified so that it possessed a counter charge to attract graphene oxide (GO). Next, the as-obtained GO-CMO composites were treated hydrothermally to generate the reduced graphene oxide (G-CMO) composites. The sensitivity of the optimal composite G-CMO#3 (11.01 μA mM-1) is much higher than that of CMO. The linear range of G-CMO#3 (5 M to 0.5 mM) is shorter than that of CMO (0.5 mM -30 mM). These results may be due to the maturity of the nanostructures on CMO and the graphene content of the G-CMO composites.