Activating Basal Planes and S-Terminated Edges of MoS₂ toward More Efficient Hydrogen Evolution

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• 作者：Xiaolei Huang ; Mei Leng ; Wen Xiao ; Meng Li ; Jun Ding ; Teck Leong Tan ; Wee Siang Vincent Lee and Junmin Xue
• 刊名：Advanced Functional Materials
• 出版年：2017
• 出版时间：February 10, 2017
• 年：2017
• 卷：27
• 期：6
• 全文大小：1636K
• ISSN：1616-3028

文摘

Molybdenum disulfide (MoS₂) has been considered as a promising alternative to platinum (Pt)-based catalyst for hydrogen evolution reaction (HER) due to its low cost and high catalytic activity. However, stable 2H phase of MoS₂ (2H-MoS₂) exhibits low catalytic activity in HER due to the inert basal plane and S-edge. Thus, to exploit the basal plane and S-edge for additional electrocatalytic activity, a facile strategy is developed to prepare P-doped 2H-MoS₂ film on conductive substrate via low-temperature heat treatment. Due to the inherent difficulty of P-doping into MoS₂ crystal structure, oxygen (O)-doping is utilized to aid the P-doping process, as supported by the first-principles calculations. Interestingly, P-doping could dramatically reduce Mo valence charge, which results in the functionalization of the inert MoS₂ basal plane and S-edge. In agreement with simulation results, P-doped 2H-MoS₂ electrode exhibits enhanced catalytic performance in H₂ generation with low onset potential (130 mV) and small Tafel slope of 49 mV dec⁻¹. The enhanced catalytic performance arises from the synergistic effect of the activated basal plane, S-edge, and Mo-edge sites, leading to favorable hydrogen adsorption energies. Most importantly, improved cyclic stability is achieved, which reveals chemically inert properties of P-doped 2H-MoS₂ in acidic electrolyte.