Issue 31, 2017

Co9S8@N,P-doped porous carbon electrocatalyst using biomass-derived carbon nanodots as a precursor for overall water splitting in alkaline media

Abstract

In this study, we first synthesized Co9S8@N-doped porous carbon (Co9S8@NC) using shrimp-shell derived carbon nanodots as a carbon/nitrogen source in the presence of CoSO4 by a one-step molten-salt calcination method. This was followed by low-temperature phosphorization in the presence of NaH2PO2, whereby Co9S8@N,P-doped porous carbon (Co9S8@NPC) was finally obtained using the Co9S8@NC as a precursor. The results demonstrated that the molten-salt calcination approach can effectively create a pyrolytic product with a porous structure and improve the material’s surface area, which is favourable for electrocatalysis-related mass transport and the exposure of catalytic active sites during electrocatalysis. As an electrocatalyst, Co9S8@NPC exhibits higher catalytic activity for the hydrogen evolution reaction (HER) than Co9S8@NC in an alkaline medium. Among all the investigated Co9S8@NPC catalysts, Co9S8@NPC-10 (mass ratio of NaH2PO2 to Co9S8@NC = 10 : 1) displays the best HER activity with an overpotential of 261 mV at 10 mA cm−2 in the alkaline medium. Interestingly, Co9S8@NPC-10 also displays good catalytic activity for the oxygen evolution reaction (OER) in this study. Owing to its bifunctional catalytic activity towards the HER and OER, the fabricated Co9S8@NPC-10 was simultaneously used as an anode and cathode material to generate O2 and H2 from overall water splitting in the alkaline medium, exhibiting a nearly 100% faradaic yield. This study would be helpful to the design and development of high performance non-precious metal electrocatalysts to be applied in overall water splitting to produce H2 and O2.

Graphical abstract: Co9S8@N,P-doped porous carbon electrocatalyst using biomass-derived carbon nanodots as a precursor for overall water splitting in alkaline media

Supplementary files

Article information

Article type
Paper
Submitted
13 fev 2017
Accepted
14 mar 2017
First published
31 mar 2017
This article is Open Access
Creative Commons BY license

RSC Adv., 2017,7, 19181-19188

Co9S8@N,P-doped porous carbon electrocatalyst using biomass-derived carbon nanodots as a precursor for overall water splitting in alkaline media

R. Liu, H. Zhang, X. Zhang, T. Wu, H. Zhao and G. Wang, RSC Adv., 2017, 7, 19181 DOI: 10.1039/C7RA01798G

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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