X射线光电子能谱
退火(玻璃)
二硫化钼
材料科学
扫描电子显微镜
催化作用
化学工程
氢
介电谱
电催化剂
电化学
分析化学(期刊)
化学
复合材料
电极
物理化学
有机化学
工程类
作者
Mengci He,Fanpeng Kong,Geping Yin,Zhe Lv,Xiudong Sun,Hongyan Shi,Bo Gao
出处
期刊:RSC Advances
[The Royal Society of Chemistry]
日期:2018-01-01
卷期号:8 (26): 14369-14376
被引量:36
摘要
Molybdenum disulfide (MoS2) is a promising electrocatalyst for hydrogen evolution reaction (HER), but only edges and S-vacancies are catalytic active sites for the HER. Therefore, it is crucial to increase edge sites and S-vacancies for enhancing the HER activity of MoS2. Here, we report an enhanced HER activity of MoS2 by combing vertical nanosheets and H2 annealing. Compared to horizontal MoS2 nanosheets, pristine vertical MoS2 nanosheets showed better HER activity due to a larger amount of edges. H2 annealing further enhanced the HER activity of vertical MoS2 nanosheets remarkably. Scanning electron microscopy (SEM), X-ray photoelectron spectra (XPS) and electrochemical impedance spectroscopy (EIS) were used to elucidate the enhanced HER activity by H2 annealing. SEM images showed that H2 annealing roughened the MoS2 edges, leading to more edge sites. XPS data revealed the smaller S : Mo ratio after H2 annealing, meaning more S-vacancies. Meanwhile, EIS measurements showed that charge transfer was accelerated by H2 annealing. These findings elaborated the H2 annealing induced enhancement of the HER activity, which were further confirmed by the subsequent re-sulfurization experiment.
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