Kim, Nam-In Afzal, Rana Arslan Choi, Sung Ryul Lee, Sung Won Ahn, Docheon Bhattacharjee, Satadeep Lee, Seung-Cheol Kim, Jung Hyun Park, Jun-Young 2024-01-20T01:02:50Z 2024-01-20T01:02:50Z 2021-08-31 2017-07-07 2050-7488 https://pubs.kist.re.kr/handle/201004/122536 A-site cation doping in perovskite-based materials with the general ABO(3) formula has a significant effect on the bifunctional oxygen activity (oxygen evolution and reduction reactions) of chemically stable electrocatalysts, enabling the design of highly active, durable, and cost-effective catalysts. In particular, the oxygen activity of double perovskite-structured NdBa0.5Sr0.5Co1.5Fe0.5O5+delta (NBSCF) is 0.973 V, which is much greater than that of previously reported transition metal-based nanostructures. This result is verified by examination of the electronic structure, oxidation state, and electrical properties of the perovskite-based materials using density functional theory (DFT) calculations, the iodometric titration method, X-ray photon spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS) analysis. Further improvements of NBSCF for bifunctional oxygen activity are made by incorporating these synergistic hybrid structures with nitrogen doped-reduced graphene-based (N-rGO) nanostructures (NBSCF/N-rGO). The NBSCF/N-rGO has an oxygen electrode activity of 0.766 V, which is superior to that of other previously reported transition metal-based nanostructures and compares favorably to that of precious metal electrocatalysts. Furthermore, strong N-rGO provides considerably greater electrochemical long-term stability and integrity to NBSCF/N-rGO hybrid catalysts under continuous chronopotentiometric and long-term potential sweep testing conditions for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). English ROYAL SOC CHEMISTRY OXYGEN-REDUCTION COBALT OXIDE FUEL-CELLS ELECTROCATALYTIC ACTIVITY WATER OXIDATION METAL-FREE IN-SITU EVOLUTION AIR CARBON Highly active and durable nitrogen doped-reduced graphene oxide/double perovskite bifunctional hybrid catalysts Article 10.1039/c7ta02283b 1 JOURNAL OF MATERIALS CHEMISTRY A, v.5, no.25, pp.13019 - 13031 JOURNAL OF MATERIALS CHEMISTRY A 5 25 13019 13031 scie scopus 000404571500043 2-s2.0-85021660157 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Chemistry Energy & Fuels Materials Science Article OXYGEN-REDUCTION COBALT OXIDE FUEL-CELLS ELECTROCATALYTIC ACTIVITY WATER OXIDATION METAL-FREE IN-SITU EVOLUTION AIR CARBON perovskite catalyst N-doped graphene oxide density functional theory BSCF LBSCF oxygen evolution reaction oxygen reduction reaction