Facile synthesis of Cu doped cobalt hydroxide (Cu–Co(OH) 2 ) nano-sheets for efficient electrocatalytic oxygen evolution

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2017, Vol.5 (43), p.22568-22575
• Main Authors: Chen, Lisong, Zhang, Huilin, Chen, Li, Wei, Xinfa, Shi, Jianlin, He, Mingyuan
• Format: Article
• Language: English
• Subjects: Catalysis; Catalytic activity; Chemical plants; Cobalt; Doping; Durability; Electronic structure; Hydroxides; Oxygen; Oxygen evolution reactions; Photoelectron spectroscopy; Sheets; Synthesis; X ray photoelectron spectroscopy
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/C7TA07637A

We report herein the facile synthesis of cobalt hydroxide nano-sheets with a uniform ultrathin structure under mild conditions. By doping heteroatoms such as Cu, the nanosheets' morphology and dimension can be well-tuned. The prepared heteroatom-doped cobalt hydroxide nano-sheets exhibit excellent catalytic activity and durability toward the oxygen evolution reaction (OER). In particular, Cu-doped cobalt hydroxide (Cu–Co(OH) 2 ) shows an electrocatalytic current density of 10 mA cm −2 and a mass activity of 46 A g −1 at the overpotential of 300 mV, and a Tafel slope of 47 mV dec −1 , which are markedly higher than those of the state-of-the-art IrO 2 . Importantly, X-ray photoelectron spectroscopy (XPS) suggests the modulated electronic structure by the heteroatom doping, which implies that Co ions are more positively charged than the normal 2+ and is thus in favor of the OER performance. This work presents a green and facile strategy for the synthesis of heteroatom in situ doped ultrathin hydroxides which show excellent performance for the OER. A possible OER mechanism of this heteroatom doped Co(OH) 2 material has also been proposed.