Tailoring Co(OH)2 hollow nanostructures via Cu2O template etching for high performance supercapacitors

Huan Yang; Jiale Xie; Shu juan Bao; Chang Ming Li

doi:10.1016/j.jcis.2015.07.018

Tailoring Co(OH)2 hollow nanostructures via Cu2O template etching for high performance supercapacitors

J Colloid Interface Sci. 2015 Nov 1:457:212-7. doi: 10.1016/j.jcis.2015.07.018. Epub 2015 Jul 10.

Authors

Huan Yang¹, Jiale Xie¹, Shu juan Bao¹, Chang Ming Li²

Affiliations

¹ Institute for Clean Energy & Advanced Materials, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Chongqing 400715, China; Faculty of Materials and Energy, Southwest University, Chongqing 400715, China.
² Institute for Clean Energy & Advanced Materials, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Chongqing 400715, China; Faculty of Materials and Energy, Southwest University, Chongqing 400715, China. Electronic address: ecmli@swu.edu.cn.

PMID: 26188727
DOI: 10.1016/j.jcis.2015.07.018

Abstract

Co(OH)2 hollow nanostructures including cube, octahedron and flower are delicately tailored via a simple and fast one-step Cu2O template etching method. The as-prepared materials were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission scanning electron microscope (FESEM), N2 adsorption-desorption and electrochemical methods and X-ray photoelectron spectroscopy (XPS). In particular, the supercapacitive behaviors of the as-prepared materials were investigated to explore relation of capacitance versus nanostructure. Results indicate that the as-prepared Co(OH)2 samples inherit the size and shape of the Cu2O templates but with an inside hollow, and the differently nanostructured Co(OH)2 exhibits different capacitive behaviors. Among various morphologies, the flower Co(OH)2 has the largest specific capacitance of 1350 F/g, while octahedron Co(OH)2 has the smallest one of 986.4 F/g. This is mainly because the flower Co(OH)2 not only has the largest available surface area, but also offers the fast interfacial electron transfer for higher pseudocapacitance and enhanced electrolyte ion diffusion rate for high power density, which is supported by both theoretical calculation, measured BET data and ac impedance measurements. This work may provide a vivid example to rationally design a nanostructure and further explore its fundamental insights for high performance supercapacitors.

Keywords: Co(OH)(2); Cu(2)O hard template; Morphology tailoring; Supercapacitor.