物理化学学报2020，Vol.36Issue(3)：12-21,10.DOI:10.3866/PKU.WHXB201901051
SiC/Pt/CdS纳米棒Z型异质结的制备及其高效光催化产氢性能
Fabrication of Z-Scheme Heterojunction of SiC/Pt/Cds Nanorod for Efficient Photocatalytic H2 Evolution
摘要
Abstract
In this study, a novel silicon carbide/platinum/cadmium sulfide (SiC/Pt/CdS) Z-scheme heterojunction nanorod is constructed using a simple chemical reduction-assisted hydrothermal method, in which Pt nanoparticles are anchored at the interface of SiC nanorods and CdS nanoparticles to induce an electron-hole pair transfer along the Z-scheme transport path. Multiple characterization techniques are used to analyze the structure, morphology, and properties of these materials. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results show that the SiC/Pt/CdS materials with good crystalstructure are successfully synthesized. Transmission electron microscopy reveals that Pt nanoparticles grow between the interfaces of SiC nanorods and CdS nanoparticles. UV-Vis diffuse reflectance spectroscopy shows that the as-prepared Z-scheme heterojunction samples have a wider light absorption range in comparison with pristine CdS materials. Photoluminescence spectroscopy and the transient photocurrent response further demonstrate that the SiC/Pt/CdS nanorod sample with an optimal molar ratio possesses the highest electron-hole pair separation efficiency. The loading amount of CdS on the surface of SiC/Pt nanorods is effectively adjusted by controlling the molar ratio of SiC and CdS to achieve the optimal performance of the SiC/Pt/CdS nanorod photocatalysts. The optimal H2 evolution capacity is achieved at SiC : CdS = 5 : 1 (molar ratio) and the maximum H2 evolution rate reaches a high value of 122.3 μmol·h?1. In addition, scanning electron microscopy, XRD, and XPS analyses show that the morphology and crystal structure of the SiC/Pt/CdS photocatalyst remain unchanged after three cycles of activity testing, indicating that the SiC/Pt/CdS nanocomposite has a stable structure for H2 evolution under visible light. To prove the Z-scheme transfer mechanism of electron-hole pairs, selective photo-deposition technology is used to simultaneously carry out the photo-reduction deposition of Au nanoparticles and photo-oxidation deposition of Mn3O4 nanoparticles in the photoreaction. The experimental results indicate that during photocatalysis, the electrons in the conduction band of CdS participate mainly in the reduction reaction, and the holes in the valence band of SiC are more likely to undergo the oxidation reaction. The electrons in the conduction band of SiC combine with the holes in the valence band of CdS to form a Z-scheme transport path. Therefore, a possible Z-scheme charge migration path in SiC/Pt/CdS nanorods during photocatalytic H2 production is proposed to explain the enhancement in the activity. This study provides a new strategy for synthesizing a Z-scheme photocatalytic system based on SiC nanorods. Based on the characterization results, it is determined that SiC/Pt/CdS nanocomposites are highly efficient, inexpensive, easy to prepare, and are stable structures for H2 evolution under visible light with outstanding commercial application prospects.关键词
碳化硅/纳米棒/SiC/Pt/CdS/光催化剂/Z型异质结Key words
SiC/Nanorod/SiC/Pt/CdS/Photocatalyst/Z-scheme heterojunction分类
化学化工引用本文复制引用
曹丹,安华,严孝清,赵宇鑫,杨贵东,梅辉..SiC/Pt/CdS纳米棒Z型异质结的制备及其高效光催化产氢性能[J].物理化学学报,2020,36(3):12-21,10.基金项目
The project was supported by the National Natural Science Foundation of China (U1862105), Natural Science Basic Research Plan in Shaanxi Province of China (2017JZ001, 2018KJXX-008), Key Research and Development Program of Shaanxi Province, China (2018ZDCXL-SF-02-04), Fundamental Research Funds for the Central Universities, China (cxtd2017004), and K. C. Wong Education Foundation and Hong Kong, China.国家自然科学基金(U1862105), 陕西省自然科学基础研究计划(2017JZ001, 2018KJXX-008), 陕西省重点研发计划(2018ZDCXL-SF-02-04), 中央基本科研业务费(cxtd2017004)以及王宽诚教育基金会的资助 （U1862105）
