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  • Synthesis of defect-engineered molybdenum sulfides on reduced graphene oxide for enhanced hydrogen evolution reaction kinetics
Title: Synthesis of defect-engineered molybdenum sulfides on reduced graphene oxide for enhanced hydrogen evolution reaction kinetics
Amorphous molybdenum sulfide (a-MoS3) is a promising non-precious electrocatalyst for hydrogen evolution reaction owing to the abundant defective active sites. Here in, we show a rapid microwave-assisted synthesis method to produce a-MoS3 catalysts on reduced graphene oxide (rGO) substrates. The a-MoS3 reported in this study comprise of two possible 1D chain-like structures, i.e., with molybdenum (IV) in Weber’s model and molybdenum (V) in Hibble’s model, unlike the polymeric cluster type a-MoS3 structures reported in literature. Thermal annealing of the microwave-prepared a-MoS3 produced a family of defect-engineered MoSx/rGO hybrids, from a-MoS3 to crystalline MoS2, which showed tunable HER activities. XPS analysis provided in-depth understanding of the compositional changes in MoSx/rGO with thermal annealing. The a-MoS3/rGO 250 (annealed at 250 ◦C) exhibited the highest HER catalytic activity among all the MoSx/rGO hybrids, with an overpotential of 208 mV at 10 mA/cm2, a low Tafel slope of 52 mV/decade, a high double layer capacitance of 3.7 mF/cm2 and a high TOF value of 0.43 H2/s per site at the HER overpotential of 208 mV. The excellent HER activity is attributed to both MoV and sulfur active sites. This study provides a controllable, scalable and rapid synthesis method to produce 1D chain-like a-MoS3 structures for HER electrocatalysis.  more » « less
Award ID(s):
2054754 1707585
PAR ID:
10511119
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
Elsevier
Date Published:
Journal Name:
International Journal of Hydrogen Energy
Volume:
51
Issue:
PC
ISSN:
0360-3199
Page Range / eLocation ID:
1387 to 1396
Subject(s) / Keyword(s):
Molybdenum sulfide Hydrogen evolution reaction Electrocatalyst Defect engineering Hybrid materials
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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