TY - JOUR
T1 - Engineering additional edge sites on molybdenum dichalcogenides toward accelerated alkaline hydrogen evolution kinetics
AU - Zhou, Qian
AU - Zhao, Guoqiang
AU - Rui, Kun
AU - Chen, Yaping
AU - Xu, Xun
AU - Dou, Shi Xue
AU - Sun, Wenping
N1 - Publisher Copyright:
© 2019 The Royal Society of Chemistry.
PY - 2019/1/14
Y1 - 2019/1/14
N2 - The sluggish reaction kinetics of the hydrogen evolution reaction (HER) in alkaline media is a great obstacle to alkaline water electrolysis, and it remains a great challenge to develop precious metal-free efficient catalysts for the alkaline HER. Transition metal dichalcogenides (TMDs), in particular MoS 2 and MoSe 2 , are promising catalysts for the HER in acidic media, but they exhibit much inferior catalytic activity for the alkaline HER owing to the slow water dissociation process. In this work, we, for the first time, demonstrate that TMD heterostructures with abundant edge sites deliver substantially accelerated alkaline HER kinetics, which is in great part due to the enhanced water adsorption/dissociation capability. As a proof of concept, MoS 2 /MoSe 2 heterostructures with ultrasmall MoS 2 nanoclusters anchored on MoSe 2 nanosheets are synthesized via a solution-phase process and are investigated as alkaline HER catalysts in detail. MoSe 2 nanosheets serve as excellent substrates to hinder the agglomeration of MoS 2 nanoclusters, resulting in abundant edge sites. Benefiting from the decent water adsorption/dissociation capability of the edge sites, the optimal MoS 2 /MoSe 2 heterostructure shows exceptional catalytic activity in 1 M KOH with an overpotential of 235 mV at 10 mA cm -2 and a Tafel slope of 96 mV dec -1 , which is substantially improved as compared with the individual MoSe 2 (330 mV, 135 mV dec -1 ) and MoS 2 (400 mV, 157 mV dec -1 ). The success of this catalyst design strategy for enhancing alkaline HER kinetics is also demonstrated in MoSe 2 /MoSe 2 and MoS 2 /MoS 2 heterostructures. The results suggest that engineering additional edge sites that have a strong affinity for H 2 O is critical for TMDs towards enhanced alkaline HER activity, and also open new avenues in the design of precious metal-free efficient catalysts for the alkaline HER.
AB - The sluggish reaction kinetics of the hydrogen evolution reaction (HER) in alkaline media is a great obstacle to alkaline water electrolysis, and it remains a great challenge to develop precious metal-free efficient catalysts for the alkaline HER. Transition metal dichalcogenides (TMDs), in particular MoS 2 and MoSe 2 , are promising catalysts for the HER in acidic media, but they exhibit much inferior catalytic activity for the alkaline HER owing to the slow water dissociation process. In this work, we, for the first time, demonstrate that TMD heterostructures with abundant edge sites deliver substantially accelerated alkaline HER kinetics, which is in great part due to the enhanced water adsorption/dissociation capability. As a proof of concept, MoS 2 /MoSe 2 heterostructures with ultrasmall MoS 2 nanoclusters anchored on MoSe 2 nanosheets are synthesized via a solution-phase process and are investigated as alkaline HER catalysts in detail. MoSe 2 nanosheets serve as excellent substrates to hinder the agglomeration of MoS 2 nanoclusters, resulting in abundant edge sites. Benefiting from the decent water adsorption/dissociation capability of the edge sites, the optimal MoS 2 /MoSe 2 heterostructure shows exceptional catalytic activity in 1 M KOH with an overpotential of 235 mV at 10 mA cm -2 and a Tafel slope of 96 mV dec -1 , which is substantially improved as compared with the individual MoSe 2 (330 mV, 135 mV dec -1 ) and MoS 2 (400 mV, 157 mV dec -1 ). The success of this catalyst design strategy for enhancing alkaline HER kinetics is also demonstrated in MoSe 2 /MoSe 2 and MoS 2 /MoS 2 heterostructures. The results suggest that engineering additional edge sites that have a strong affinity for H 2 O is critical for TMDs towards enhanced alkaline HER activity, and also open new avenues in the design of precious metal-free efficient catalysts for the alkaline HER.
UR - http://www.scopus.com/inward/record.url?scp=85059501447&partnerID=8YFLogxK
U2 - 10.1039/c8nr08028c
DO - 10.1039/c8nr08028c
M3 - 文章
C2 - 30565626
AN - SCOPUS:85059501447
SN - 2040-3364
VL - 11
SP - 717
EP - 724
JO - Nanoscale
JF - Nanoscale
IS - 2
ER -