Issue 2, 2020

The feasibility of hollow echinus-like NiCo2O4 nanocrystals for hybrid capacitive deionization

Abstract

Hybrid capacitive deionization (HCDI) has emerged to address the shortcomings of CDI in high-salinity solutions. Cathodes for HCDI with active Faradaic reaction ability are desirable. In this work, we propose a facile method to prepare hollow echinus-like NiCo2O4 nanocrystals as high-performance cathodes for HCDI. It was determined that the specific surface area of NiCo2O4 is ∼70.74 m2 g−1 with the mean pore diameter of 20.72 nm. The electrochemical analysis demonstrated that NiCo2O4 possesses high specific capacity, remarkable capacitance retention and low impedance. As a cathode for HCDI, NiCo2O4 exhibited high salt removal capacity of 44.3 mg g−1 with charge efficiency of 98.7% at 1.2 V in an NaCl solution with initial conductivity of 1000 μS cm−1. This is attributed to the definite redox reaction between NiCo2O4 and sodium ions during the charge/discharge process. Moreover, the HCDI behavior of NiCo2O4 in various solutions containing K+, Na+ and Mg2+ was explored, illustrating that the ionic radius has priority in HCDI. Furthermore, the salt removal capacity of the NiCo2O4 electrode after 20 cycles was still ∼42.9 mg g−1, which was 97.5% of the initial value, proving its prominent regeneration.

Graphical abstract: The feasibility of hollow echinus-like NiCo2O4 nanocrystals for hybrid capacitive deionization

Supplementary files

Article information

Article type
Communication
Submitted
21 अक्तूबर 2019
Accepted
04 दिसम्बर 2019
First published
05 दिसम्बर 2019

Environ. Sci.: Water Res. Technol., 2020,6, 283-289

The feasibility of hollow echinus-like NiCo2O4 nanocrystals for hybrid capacitive deionization

Z. Liu, W. Xi and H. Li, Environ. Sci.: Water Res. Technol., 2020, 6, 283 DOI: 10.1039/C9EW00939F

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