Issue 34, 2021

Partial sulfur vacancies created by carbon–nitrogen deposition of MoS2 for high-performance overall electrocatalytic water splitting

Abstract

Electrocatalytic water splitting is a promising energy-efficient solution to obtain clean hydrogen energy. Bifunctional electrocatalysts made up of cheap and abundant elements and suitable for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) are critically needed, yet their performance deserves substantial improvement. The catalytic activity could be improved by creating unsaturated defects, which so far has rarely been demonstrated. Here, we combine the effects of unsaturated sulfur vacancies and bi-elemental C and N doping in MoS2 nanosheets to achieve high-performance bifunctional electrocatalysts. The new method to obtain C and N doped MoS2 at high temperature is presented. The obtained C–N-MoS2/CC-T catalysts with S unsaturated defect sites and Mo–N links exhibit high activity and improved electrical conductivity for both the HER and OER in alkaline media. Systematic experiments and density functional theory (DFT) analysis confirm that CN-doping exposes catalytically active sites and enhances water adsorption. The optimized C–N-MoS2/CC-700 catalyst exhibits low overpotentials of 90 and 230 mV at 10 mA cm−2 for the HER and OER, respectively. Importantly, the porous C–N-MoS2/CC-700 nanosheets deliver low voltages of 1.58 V for the overall water splitting at 10 mA cm−2 and robust operation for 30 h without any reduced activity. Such impressive performances are attributed to their unique structure with large specific surface area, abundant S unsaturated sites, Mo–N links, and shortened electron transfer paths. This partial defect filling by the bi-dopant incorporation approach is generic and is promising for a broad range of advanced energy materials.

Graphical abstract: Partial sulfur vacancies created by carbon–nitrogen deposition of MoS2 for high-performance overall electrocatalytic water splitting

Supplementary files

Article information

Article type
Paper
Submitted
09 May 2021
Accepted
27 Jul 2021
First published
27 Jul 2021

Nanoscale, 2021,13, 14506-14517

Partial sulfur vacancies created by carbon–nitrogen deposition of MoS2 for high-performance overall electrocatalytic water splitting

W. Chen, W. Wei, K. Wang, J. Cui, X. Zhu and K. (. Ostrikov, Nanoscale, 2021, 13, 14506 DOI: 10.1039/D1NR02966E

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