Ray, Chaiti Lee, Su Chan Jin, Bingjun Chung, Kyung Yoon Guo, Shiyin Zhang, Shengli Zhang, Kan Park, Jong Hyeok Jun, Seong Chan 2024-01-19T19:02:41Z 2024-01-19T19:02:41Z 2021-09-05 2019-10-01 2196-0216 https://pubs.kist.re.kr/handle/201004/119473 Most developed hydrogen evolution reaction (HER) electrocatalysts have pH-dependent functionalities, which limit their universal applications. Pt, the ideal HER electrocatalyst, is also highly effective in specific pH conditions. In the present article, we report a copper-based transition-metal chalcogenide from anion engineering. Hierarchical three-dimensional (3D) Cu2O-Cu2Se nanoflake arrays (COCS NFs) are grown directly on nickel foam (NF) by combining the rapid electrodeposition technique with the room temperature wet-chemical selenization method. Via the synergetic effects of the proper ratio of Se and O, as-synthesized COCS NFs manage to accomplish key-requirements for pH-universal HER performances with overpotential values of 52.9, 62.8, and 77.8 mV, in alkaline, neutral, and acidic media, respectively, at 10 mA cm(-2). The electrocatalyst also possesses superb stability at constant 10 mA cm(-2) current density for 50 h in all electrolytes. This work offers a synthesis protocol of a mixed-anion composite with the revelation about the importance of anion modulation towards electrode surface properties and HER performances. English WILEY-V C H VERLAG GMBH HIGHLY EFFICIENT STABLE ELECTROCATALYST EXCHANGE SYNTHESIS CARBON COPPER PERFORMANCE NANOSHEETS ELECTRODE CATALYSTS CO0.85SE Cu2O-Cu2Se Mixed-Phase Nanoflake Arrays: pH-Universal Hydrogen Evolution Reactions with Ultralow Overpotential Article 10.1002/celc.201901284 1 CHEMELECTROCHEM, v.6, no.19, pp.5014 - 5021 CHEMELECTROCHEM 6 19 5014 5021 scie scopus 000486238600001 2-s2.0-85072199556 Electrochemistry Electrochemistry Article HIGHLY EFFICIENT STABLE ELECTROCATALYST EXCHANGE SYNTHESIS CARBON COPPER PERFORMANCE NANOSHEETS ELECTRODE CATALYSTS CO0.85SE Cu2O-Cu2Se electrocatalysis ultrathin nanostructures hydrogen evolution reaction pH universality