TY - JOUR
T1 - Mos2-carbon inter-overlapped structures as effective electrocatalysts for the hydrogen evolution reaction
AU - Huang, Po Chia
AU - Wu, Chia Ling
AU - Brahma, Sanjaya
AU - Shaikh, Muhammad Omar
AU - Huang, Jow Lay
AU - Lee, Jey Jau
AU - Wang, Sheng Chang
N1 - Funding Information:
This work was supported by the Ministry of Science and Technology (MOST 108-2221-E-218-015-, 109-2221-E-218-013-and 109-2634-F-006-020-).Acknowledgments: Authors would like to thank the help from Hsing-I Hsiang. Thanks for the Southern Taiwan University of Science and Technology, National Cheng Kung University, Hierarchical Green-Energy Materials (Hi-GEM) Research Center (NCKU) and Center for Micro/Nano Science and Technology (NCKU) supporting facilities.
Funding Information:
Funding: This work was supported by the Ministry of Science and Technology (MOST 108-2221-E-218-015-, 109-2221-E-218-013-and 109-2634-F-006-020-).
Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2020/7
Y1 - 2020/7
N2 - The ability to generate hydrogen in an economic and sustainable manner is critical to the realization of a future hydrogen economy. Electrocatalytic water splitting into molecular hydrogen using the hydrogen evolution reaction (HER) provides a viable option for hydrogen generation. Consequently, advanced non-precious metal based electrocatalysts that promote HER and reduce the overpotential are being widely researched. Here, we report on the development of MoS2-carbon inter-overlapped structures and their applicability for enhancing electrocatalytic HER. These structures were synthesized by a facile hot-injection method using ammonium tetrathiomolybdate ((NH4)2 MoS4) as the precursor and oleylamine (OLA) as the solvent, followed by a carbonization step. During the synthesis protocol, OLA not only plays the role of a reacting solvent but also acts as an intercalating agent which enlarges the interlayer spacing of MoS2 to form OLA-protected monolayer MoS2. After the carbonization step, the crystallinity improves substantially, and OLA can be completely converted into carbon, thus forming an inter-overlapped superstructure, as characterized in detail using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). A Tafel slope of 118 mV/dec is obtained for the monolayer MoS2-carbon superstructure, which shows a significant improvement, as compared to the 202 mV/dec observed for OLA-protected monolayer MoS2. The enhanced HER performance is attributed to the improved conductivity along the c-axis due to the presence of carbon and the abundance of active sites due to the interlayer expansion of the monolayer MoS2 by OLA.
AB - The ability to generate hydrogen in an economic and sustainable manner is critical to the realization of a future hydrogen economy. Electrocatalytic water splitting into molecular hydrogen using the hydrogen evolution reaction (HER) provides a viable option for hydrogen generation. Consequently, advanced non-precious metal based electrocatalysts that promote HER and reduce the overpotential are being widely researched. Here, we report on the development of MoS2-carbon inter-overlapped structures and their applicability for enhancing electrocatalytic HER. These structures were synthesized by a facile hot-injection method using ammonium tetrathiomolybdate ((NH4)2 MoS4) as the precursor and oleylamine (OLA) as the solvent, followed by a carbonization step. During the synthesis protocol, OLA not only plays the role of a reacting solvent but also acts as an intercalating agent which enlarges the interlayer spacing of MoS2 to form OLA-protected monolayer MoS2. After the carbonization step, the crystallinity improves substantially, and OLA can be completely converted into carbon, thus forming an inter-overlapped superstructure, as characterized in detail using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). A Tafel slope of 118 mV/dec is obtained for the monolayer MoS2-carbon superstructure, which shows a significant improvement, as compared to the 202 mV/dec observed for OLA-protected monolayer MoS2. The enhanced HER performance is attributed to the improved conductivity along the c-axis due to the presence of carbon and the abundance of active sites due to the interlayer expansion of the monolayer MoS2 by OLA.
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U2 - 10.3390/nano10071389
DO - 10.3390/nano10071389
M3 - Article
AN - SCOPUS:85088162625
SN - 2079-4991
VL - 10
SP - 1
EP - 13
JO - Nanomaterials
JF - Nanomaterials
IS - 7
M1 - 1389
ER -