title: Atomic scale analysis of the enhanced electro- and photo-catalytic activity in high-index faceted porous NiO nanowires.
abstract: Catalysts play a significant role in clean renewable hydrogen fuel generation through water splitting reaction as the surface of most semiconductors proper for water splitting has poor performance for hydrogen gas evolution. The catalytic performance strongly depends on the atomic arrangement at the surface, which necessitates the correlation of the surface structure to the catalytic activity in well-controlled catalyst surfaces. Herein, we report a novel catalytic performance of simple-synthesized porous NiO nanowires (NWs) as catalyst/co-catalyst for the hydrogen evolution reaction (HER). The correlation of catalytic activity and atomic/surface structure is investigated by detailed high resolution transmission electron microscopy (HRTEM) exhibiting a strong dependence of NiO NW photo- and electrocatalytic HER performance on the density of exposed high-index-facet (HIF) atoms, which corroborates with theoretical calculations. Significantly, the optimized porous NiO NWs offer long-term electrocatalytic stability of over one day and 45 times higher photocatalytic hydrogen production compared to commercial NiO nanoparticles. Our results open new perspectives in the search for the development of structurally stable and chemically active semiconductor-based catalysts for cost-effective and efficient hydrogen fuel production at large scale.
authors.affiliation: Department of Materials Science &Engineering, CAS key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui, 230026, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Shen
authors.affiliation: Department of Materials Science &Engineering, CAS key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui, 230026, China.
authors.forename: Ali
authors.initials: A
authors.lastname: Han
authors.affiliation: Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
authors.forename: Xijun
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Electrical and Computer Engineering and Materials Science Program, University of California-San Diego, La Jolla, California 92093, USA.
authors.forename: Yun Goo
authors.initials: YG
authors.lastname: Ro
authors.affiliation: Department of Electrical and Computer Engineering and Materials Science Program, University of California-San Diego, La Jolla, California 92093, USA.
authors.forename: Alireza
authors.initials: A
authors.lastname: Kargar
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Lin
authors.affiliation: National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Hua
authors.initials: H
authors.lastname: Guo
authors.affiliation: Department of Materials Science &Engineering, CAS key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui, 230026, China.
authors.forename: Pingwu
authors.initials: P
authors.lastname: Du
authors.affiliation: Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA 94720, USA.
authors.forename: Jingyu
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Electrical and Computer Engineering and Materials Science Program, University of California-San Diego, La Jolla, California 92093, USA.
authors.forename: Shadi A
authors.initials: SA
authors.lastname: Dayeh
authors.affiliation: 1] Department of Materials Science &Engineering, CAS key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui, 230026, China [2] Synergetic Innovation Center of Quantum Information &Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xiang