TY - JOUR
T1 - Agent-assisted VSSe ternary alloy single crystals as an efficient stable electrocatalyst for the hydrogen evolution reaction
AU - HU, Peng
AU - LONG, Guankui
AU - CHATURVEDI, Apoorva
AU - WANG, Shancheng
AU - TAN, Kejie
AU - HE, Yongming
AU - ZHENG, Lu
AU - LIU, Guowei
AU - KE, Yujie
AU - ZHOU, Yang
AU - JIANG, Hui
AU - LIU, Zheng
AU - ZHANG, Mingtao
AU - LONG, Yi
N1 - This research is supported by grants from the National Research Foundation, Prime Minister's Office, Singapore under its Campus of Research Excellence and Technological Enterprise (CREATE) programme. We would like to acknowledge the Facility for Analysis, Characterization, Testing, and Simulation (FACTS), Nanyang Technological University, Singapore, for the use of their XRD, SEM and TEM facilities. P. Hu also acknowledges the Youth Innovation Team of Shaanxi Universities.
PY - 2019/7/2
Y1 - 2019/7/2
N2 - Transition metal dichalcogenides (TMDs) show promising electrical and electronic properties and potential catalytic applications in the hydrogen evolution reaction (HER). However, most TMDs suffered from low conductivity and scarcity of active edge sites. Herein, new ternary vanadium-based TMD, VSSe alloy single crystals were synthesized for the first time by agent-assisted chemical vapor transport and used as an excellent HER electrocatalyst due to the pure conductive phase and abundant active sites induced by ternary structures. Different transport agents were employed to tune the interlayer spacing, and it was found that the expansion of the (001) interlayer spacing and the co-existence of V3+ could introduce more S or Se vacancies. The exfoliated VSSe sample exhibits a lower overpotential of -180 mV at a current density of 10 mA cm-2, a Tafel slope of 87 mV dec-1, and better durability, which are comparable to or better than those of most previously reported ternary TMD systems. Consistent with the theoretical calculation results, more defects controlled by the transport agent of VCl3 give an enhanced conductivity and a lower H∗ adsorption energy, and thereby higher HER performance. By simply varying the transport agents, high-conductivity, high-purity, and high-performance TMDs can be fabricated in one step without the conventional post-treatment.
AB - Transition metal dichalcogenides (TMDs) show promising electrical and electronic properties and potential catalytic applications in the hydrogen evolution reaction (HER). However, most TMDs suffered from low conductivity and scarcity of active edge sites. Herein, new ternary vanadium-based TMD, VSSe alloy single crystals were synthesized for the first time by agent-assisted chemical vapor transport and used as an excellent HER electrocatalyst due to the pure conductive phase and abundant active sites induced by ternary structures. Different transport agents were employed to tune the interlayer spacing, and it was found that the expansion of the (001) interlayer spacing and the co-existence of V3+ could introduce more S or Se vacancies. The exfoliated VSSe sample exhibits a lower overpotential of -180 mV at a current density of 10 mA cm-2, a Tafel slope of 87 mV dec-1, and better durability, which are comparable to or better than those of most previously reported ternary TMD systems. Consistent with the theoretical calculation results, more defects controlled by the transport agent of VCl3 give an enhanced conductivity and a lower H∗ adsorption energy, and thereby higher HER performance. By simply varying the transport agents, high-conductivity, high-purity, and high-performance TMDs can be fabricated in one step without the conventional post-treatment.
UR - http://www.scopus.com/inward/record.url?scp=85068522416&partnerID=8YFLogxK
U2 - 10.1039/c9ta04287c
DO - 10.1039/c9ta04287c
M3 - Journal Article (refereed)
AN - SCOPUS:85068522416
SN - 2050-7488
VL - 7
SP - 15714
EP - 15721
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 26
ER -
