title: Metallic nickel nitride nanosheets realizing enhanced electrochemical water oxidation.
abstract: Exploring efficient and inexpensive oxygen evolution reaction (OER) electrocatalysts is of great importance for various electrochemical energy storage and conversion technologies. Ni-based electrocatalysts have been actively pursued because of their promising activity and earth abundance. However, the OER efficiency for most of the developed Ni-based electrocatalysts has been intrinsically limited due to their low electrical conductivity and poor active site exposure yield. Herein, we report metallic Ni3N nanosheets as an efficient OER electrocatalyst for the first time. The first-principles calculations and electrical transport property measurements unravel that the Ni3N is intrinsically metallic, and the carrier concentration can be remarkably improved with dimensional confinement. The EXAFS spectra provide solid evidence that the Ni3N nanosheets have disordered structure resultant of dimensional reduction, which then could provide more active sites for OER. Benefiting from enhanced electrical conductivity with metallic behavior and atomically disordered structure, the Ni3N nanosheets realize intrinsically improved OER activity compared with bulk Ni3N and NiO nanosheets. Our finding suggests that metallic nitride nanosheets could serve as a new group of OER electrocatalysts with excellent property.
authors.affiliation: †Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
authors.forename: Kun
authors.initials: K
authors.lastname: Xu
authors.affiliation: †Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
authors.forename: Pengzuo
authors.initials: P
authors.lastname: Chen
authors.affiliation: ‡CAS Key Laboratory of Materials for Energy Conversion and Department of Material Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
authors.forename: Xiuling
authors.initials: X
authors.lastname: Li
authors.affiliation: †Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Tong
authors.affiliation: †Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Ding
authors.affiliation: †Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230026, PR China.|‡CAS Key Laboratory of Materials for Energy Conversion and Department of Material Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Wu
authors.affiliation: §National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, PR China.
authors.forename: Wangsheng
authors.initials: W
authors.lastname: Chu
authors.affiliation: ∥Department of Chemical and Biomolecular Engineering, University of Akron, Akron, Ohio 44325, United States.
authors.forename: Zhenmeng
authors.initials: Z
authors.lastname: Peng
authors.affiliation: †Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
authors.forename: Changzheng
authors.initials: C
authors.lastname: Wu
authors.affiliation: †Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xie