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Nano Research

Article Title

High-metallic-phase-concentration Mo1–xWxS2 nanosheets with expanded interlayers as efficient electrocatalysts

Authors

Qun He, National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230029, China
Yangyang Wan, CAS Key Lab of Materials for Energy Conversion, CAS Center for Excellence in Nanoscience, Hefei National Laboratory for Physical Science at the Microscale, Synergetic Innovation of Quantum Information & Quantum Technology, University of Science and Technology of China, Hefei 230026, China
Hongliang Jiang, National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230029, China
Chuanqiang Wu, National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230029, China
Zhongti Sun, CAS Key Lab of Materials for Energy Conversion, CAS Center for Excellence in Nanoscience, Hefei National Laboratory for Physical Science at the Microscale, Synergetic Innovation of Quantum Information & Quantum Technology, University of Science and Technology of China, Hefei 230026, China
Shuangming Chen, National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230029, China
Yu Zhou, National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230029, China
Haiping Chen, National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230029, China
Daobin Liu, National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230029, China
Yasir A. Haleem, National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230029, China
Binghui Ge, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
Xiaojun Wu, CAS Key Lab of Materials for Energy Conversion, CAS Center for Excellence in Nanoscience, Hefei National Laboratory for Physical Science at the Microscale, Synergetic Innovation of Quantum Information & Quantum Technology, University of Science and Technology of China, Hefei 230026, China
Li Song, National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230029, China

Keywords

wet-chemistry, gram-scale synthesis, interlayer intercalation, metallic transition metal dichalcogenide, electrocatalytic water splitting

Abstract

ABSTRACT In most cases, layered transition metal dichalcogenides (LTMDs), containing metallic phases, show electrochemical behavior different from their semiconductor counterparts. Typically, two-dimensional layered metallic 1T-MoS2 demonstrates better electrocatalytic performance for water splitting compared to its 2H counterpart. However, the characteristics of low metallic phase concentration and poor stability limit its applications in some cases. Herein, we demonstrate a simple and efficient bottom-up wet-chemistry strategy for the large-scale synthesis of nanoscopic ultrathin Mo1–xWxS2 nanosheets with enlarged interlayer spacing and high metallic phase concentration. Our characterizations, including X-ray absorption fine structure spectroscopy (XAFS), high-angle annular dark-fieldscanning transmission electron microscopy (HAADF-STEM), and X-ray photoelectron spectroscopy (XPS) revealed that the metallic ultrathin ternary Mo1–xWxS2 nanosheets exhibited distorted metal–metal bonds and a tunable metallic phase concentration. As a proof of concept, this optimized catalyst, with the highest metallic phase concentration (greater than 90%), achieved a low overpotential of about –155 mV at a current density of –10 mA/cm2, a small Tafel slope of 67 mV/dec, and an increased turnover frequency (TOF) of 1.3 H2 per second at an overpotential of –300 mV (vs. reversible hydrogen electrode (RHE)), highlighting the importance of the metallic phase. More importantly, this study can lead to a facile solvothermal route to prepare stable and high-metallicphase-concentration transition-metal-based two-dimensional materials for future applications.

Graphical Abstract

Publisher

Tsinghua University Press

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