Silicon Microwire Arrays Decorated with Amorphous Heterometal-doped Molybdenum Sulfide for Water Photoelectrolysis
學年 105
學期 2
出版（發表）日期 2017-02-01
作品名稱 Silicon Microwire Arrays Decorated with Amorphous Heterometal-doped Molybdenum Sulfide for Water Photoelectrolysis
作品名稱（其他語言）
著者 C. J. Chen; K. C. Yang; C. W. Liu; Y. R. Lu; C. L. Dong; D. H. Wei; S. F. Hu; R. S. Liu
單位
出版者
著錄名稱、卷期、頁數 Nano Energy 32, p.422-432
摘要 Silicon is a promising photocathode material for solar hydrogen evolution because of its small band gap, negative conduction band position, and ideal theoretical current density. In this study, p-type Si microwire (p-Si MW) arrays were prepared as photocathodes because of the large surface area and high light-harvesting capability. However, Si MWs suffered from low photocatalytic activity because of slow photo-induced carriers during driving of water-splitting reaction. Therefore, molybdenum sulfide (MoS2) with appropriate band alignment with p-Si material was employed for surface modification to function as a co-catalyst for collecting photo-generated minority carriers and reducing recombination possibility. The onset potential and current density at 0 V versus reversible hydrogen electrode (RHE) of Si@MoS2 MWs were +0.122 V and −8.41 mA cm−2. Heterometal atoms were employed to dope MoS2 co-catalyst and expose more sulfur-terminated active sites to further boost photoelectrochemical performance. Optimal activity of Si@MMoSx (M = Fe, Co, Ni) was achieved by doping Co heteroatoms, and its turn-on voltage and photocurrent density at 0 V (vs. RHE) were respectively increased to +0.192 V and −17.2 mA cm−2. X-ray absorption spectroscopy was applied to demonstrate that Fe ions of FeMoSx were dichalcogenide materials, forming a composite with MoS2 and contributing better photoelectrolytic efficiency. By contrast, two-valent heteroatoms of CoMoSx and NiMoSx substituted the Mo4+ ions in MoS2. For charge compensation, more defects and edges were revealed as active sites of solar hydrogen production by adding Co or Ni dopants in MoS2 co-catalyst, which led to lower overpotential.
關鍵字 Water splitting;Co-catalyst;Molybdenum sulfide;Silicon microwire array;Solar hydrogen evolution
語言 en_US
ISSN 2211-2855
期刊性質 國外
收錄於 SCI
產學合作
通訊作者 R. S. Liu
審稿制度 否
國別 NLD
公開徵稿
出版型式 ,電子版
相關連結

機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/118855 )