title: Ultrathin Laminar Ir Superstructure as Highly Efficient Oxygen Evolution Electrocatalyst in Broad pH Range.
abstract: Shape-controlled noble metal nanocrystals (NCs), such as Au, Ag, Pt, Pd, Ru, and Rh are of great success due to their new and enhanced properties and applications in chemical conversion, fuel cells, and sensors, but the realization of shape control of Ir NCs for achieving enhanced electrocatalysis remains a significant challenge. Herein, we report an efficient solution method for a new class of three-dimensional (3D) Ir superstructure that consists of ultrathin Ir nanosheets as subunits. Electrochemical studies show that it delivers the excellent electrocatalytic activity toward oxygen evolution reaction (OER) in alkaline condition with an onset potential at 1.43 V versus reversible hydrogen electrode (RHE) and a very low Tafel slope of 32.7 mV decade(-1). In particular, it even shows superior performance for OER in acidic solutions with the low onset overpotential of 1.45 V versus RHE and small Tafel slope of 40.8 mV decade(-1), which are much better than those of small Ir nanoparticles (NPs). The 3D Ir superstructures also exhibit good stability under acidic condition with the potential shift of less than 20 mV after 8 h i-t test. The present work highlights the importance of tuning 3D structures of Ir NCs for enhancing OER performance.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Jiangsu, 215123, China.
authors.forename: Yecan
authors.initials: Y
authors.lastname: Pi
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Jiangsu, 215123, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 100871, China.
authors.forename: Shaojun
authors.initials: S
authors.lastname: Guo
authors.affiliation: Testing and Analysis Center, Soochow University , Jiangsu, 215123, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Guo
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Jiangsu, 215123, China.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Huang
keywords: Iridium; electrocatalysis; nanosheets; oxygen evolution reaction; three dimensional