Cobalt (oxy)hydroxide nanosheet arrays with exceptional porosity and rich defects as a highly efficient oxygen evolution electrocatalyst under neutral conditions

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 7; no. 17; pp. 1217 - 1224
• Main Authors: Chen, Minqi, Xie, Yanyu, Wu, Jun-Xi, Huang, Huanfeng, Teng, Jun, Wang, Dawei, Fan, Yanan, Jiang, Ji-Jun, Wang, Hai-Ping, Su, Cheng-Yong
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 24.04.2019
• Subjects: Buffer solutions; carbon; Cloth; Cobalt; Defects; durability; Nanosheets; Nanostructure; Oxidation; Oxygen; Oxygen evolution reactions; oxygen production; phosphates; Porosity
• ISSN: 2050-7488; 2050-7496; 2050-7496
• DOI: 10.1039/c9ta00380k

An oxidation-mediated defect and porosity enrichment strategy is developed for the synthesis of a new electrocatalyst consisting of cobalt (oxy)hydroxide nanosheet arrays (denoted as CoO x H y NSAs) grown on carbon cloth (CC), which feature a 3D hierarchical nanostructure with exceptional porosity and rich defects. The CoO x H y /CC shows exceptional activity and stability for the oxygen evolution reaction under neutral conditions, as indicated by its high current density of 38 mA cm −2 at 1.8 V, small Tafel slope of 121 mV dec −1 , low overpotential of 430 mV, and 24 h durability at 10 mA cm −2 in 0.1 M phosphate buffer solution (PBS). Highly porous and defective cobalt (oxy)hydroxide nanosheet arrays rank the best cobalt-based noble-metal-free oxygen evolution electrocatalyst under neutral conditions.