Issue 38, 2017

Phase and morphology evolution of ultrathin Co(OH)2 nanosheets towards supercapacitor application

Abstract

Ultrathin α-Co(OH)2 nanosheets (NSs) were hydrothermally synthesized without using surfactants and templates. Interestingly, the ultrathin α-Co(OH)2 NSs evolved from graphene-like NSs to hexagonal nanoplates (NPs) and then transformed into a needle-like Co(CO3)0.5(OH)·0.11H2O phase with increasing reaction temperature and time. The phase and morphology evolution depended strongly on the CO32− ions in the solution. We ruled out the possibility that CO32− originated from the adsorption of CO2 in air and proposed the possible phase transition mechanism from α-Co(OH)2 to Co(CO3)0.5(OH)·0.11H2O, which was due to the decomposition of hexamethylenetetramine driven by dynamics and thermodynamics. The morphology evolution could be regarded as the dissolution–recrystallization–redissolution–recrystallization of α-Co(OH)2. The electrochemical behavior tests demonstrated that the ultrathin α-Co(OH)2 electrode exhibited an excellent specific capacitance of 833.4 F g−1 at 5 A g−1; however, the specific capacitance of the needle-like Co(CO3)0.5(OH)·0.11H2O electrode was 247.2 F g−1 at the same current density. This excellent electrochemical property is attributed to the crystalline phase and ultrathin nature of the materials.

Graphical abstract: Phase and morphology evolution of ultrathin Co(OH)2 nanosheets towards supercapacitor application

Article information

Article type
Paper
Submitted
16 Jun 2017
Accepted
22 Aug 2017
First published
23 Aug 2017

CrystEngComm, 2017,19, 5780-5786

Phase and morphology evolution of ultrathin Co(OH)2 nanosheets towards supercapacitor application

K. Ding, X. Zhang, J. Li, P. Yang and X. Cheng, CrystEngComm, 2017, 19, 5780 DOI: 10.1039/C7CE01130J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements