Mesoporous nitrogen, sulfur co-doped carbon dots/CoS hybrid as an efficient electrocatalyst for hydrogen evolution

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 5; no. 6; pp. 2717 - 2723
• Main Authors: Wang, Liping, Wu, Xiuqin, Guo, Sijie, Han, Mumei, Zhou, Yunjie, Sun, Yue, Huang, Hui, Liu, Yang, Kang, Zhenhui
• Format: Journal Article
• Language: English
• Published: 2017
• Subjects: Carbon; Electrocatalysts; Heat treatment; Hydrogen evolution; Nanoparticles; Nitrogen; Renewable energy; Sulfur
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c6ta09580a

Hydrogen is an ideal energy carrier for renewable energy, but a high overpotential is required to achieve reasonable H2 evolution, which makes the design of highly active electrocatalysts for hydrogen evolution reaction (HER) urgent. Here, we report a nitrogen, sulfur co-doped carbon dots (NSCDs)/CoS hybrid with a three-dimensional mesoporous sponge-like nanostructure, fabricated via heat-treatment, which as electrocatalyst exhibits the desired electrocatalytic activity for electrochemical HER. A series of NSCDs/CoS hybrids with different contents of NSCDs were prepared by adjusting the concentration of NSCDs, of which the NSCDs/CoS hybrid with 20 mg L-1 NSCDs exhibits the best electrocatalytic activity towards HER with an onset potential of 0.095 V, an overpotential at 10 mA cm-2 of 165 mV, a small Tafel slope of 56 mV per decade, and a good stability in 0.5 M H2SO4. The excellent electrocatalytic activity of NSCDs/CoS for HER is attributed to synergetic effects of NSCDs and CoS, in which the NSCDs could protect the CoS from dissolution/agglomeration under acidic conditions, and the increased surface area of the NSCDs/CoS hybrid and the high charge transfer efficiency between NSCDs and CoS via Co-S-C bonding enhanced the HER performance.