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Three-Dimensional Hierarchical Frameworks Based on MoS2 Nanosheets Self-Assembled on Graphene Oxide for Efficient Electrocatalytic Hydrogen Evolution

Zhou, Weijia, Zhou, Kai, Hou, Dongman, Liu, Xiaojun, Li, Guoqiang, Sang, Yuanhua, Liu, Hong, Li, Ligui, Chen, Shaowei
ACS Applied Materials & Interfaces 2014 v.6 no.23 pp. 21534-21540
Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, electrical conductivity, glassy carbon electrode, graphene oxide, hydrogen production, nanosheets, oxygen, renewable energy sources, strength (mechanics), transmission electron microscopy
Advanced materials for electrocatalytic water splitting are central to renewable energy research. In this work, three-dimensional (3D) hierarchical frameworks based on the self-assembly of MoS₂ nanosheets on graphene oxide were produced via a simple one-step hydrothermal process. The structures of the resulting 3D frameworks were characterized by using a variety of microscopic and spectroscopic tools, including scanning and transmission electron microscopies, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman scattering. Importantly, the three-dimensional MoS₂/graphene frameworks might be used directly as working electrodes which exhibited apparent and stable electrocatalytic activity in hydrogen evolution reaction (HER), as manifested by a large cathodic current density with a small overpotential of −107 mV (−121 mV when loaded on a glassy-carbon electrode) and a Tafel slope of 86.3 mV/dec (46.3 mV/dec when loaded on a glassy-carbon electrode). The remarkable performance might be ascribed to the good mechanical strength and high electrical conductivity of the 3D frameworks for fast charge transport and collection, where graphene oxide provided abundant nucleation sites for MoS₂ deposition and oxygen incorporation led to the formation of defect-rich MoS₂ nanosheets with active sites for HER.