Jung, Namgee Shin, Hyeyoung Kim, Mansu Jang, Injoon Kim, Hyoung-Juhn Jang, Jong Hyun Kim, Hyungjun Yoo, Sung Jong 2024-01-20T06:02:57Z 2024-01-20T06:02:57Z 2021-09-04 2015-10 2211-2855 https://pubs.kist.re.kr/handle/201004/124971 Direct electrostatic interactions between a charged Pt surface and oppositely charged spectator ions are utilized for the enhancement of oxygen reduction reaction (ORR) activity in both KOH and H3PO4 solutions. Zwitterionic L-cysteine molecules functionalized on a Pt surface are turned outwards to afford differing surface charges in either alkaline (-) or acid solutions (+). In KOH solution, this leads to the selective impediment of interactions between OH- and K+ with the Pt surface through repulsive and attractive interactions of the negatively charged -COO- group of L-cysteine, respectively. In H3PO4 solution, the phosphoric acid molecule and its anion are effectively captured by the positively charged -NH3+ moieties of L-cysteine. Behaviors of the spectator species hindering the ORR are systematically controlled through direct electrostatic interactions with the functional groups of L-cysteine in each electrolyte, resulting in a Janus Pt catalyst for superior ORR in both alkaline and acid electrolytes. (C) 2015 Elsevier Ltd. All rights reserved. English ELSEVIER SCIENCE BV Janus Pt surfaces derivatized with zwitterionic molecules for oxygen reduction reactions in alkaline and acid electrolytes Article 10.1016/j.nanoen.2015.08.012 1 NANO ENERGY, v.17, pp.152 - 159 NANO ENERGY 17 152 159 N scie scopus 000366149000017 2-s2.0-84941889860 Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Chemistry Science & Technology - Other Topics Materials Science Physics Article SELF-ASSEMBLED MONOLAYERS FUEL-CELLS ELECTROCATALYTIC ACTIVITY GOLD ELECTRODE L-CYSTEINE NANOPARTICLES PLATINUM CATALYSTS CARBON ELECTROREDUCTION Oxygen reduction reaction Zwitterionic molecules Spectator ions Bifunctional electrocatalyst Fuel cell