ZnO@ZnS decorated Ni foam and PbS@CuS core-shell nanomaterials for photocatalytic H2 production
Autor: | HUANG,CI-YOU, 黃綮宥 |
---|---|
Rok vydání: | 2019 |
Druh dokumentu: | 學位論文 ; thesis |
Popis: | 107 In the first part of this study, the ZnO@ZnS core shell nanorods decorated Ni foam as an immobilized photocatalyst for hydrogen production was prepared by a two-step process, including the formation of ZnO nanorod core by a hydrothermal method and the fabrication of ZnS shell by a sulfidation method. The crystal lattice was analyzed by XRD. FESEM and FETEM were applied to observe the surface morphology and ZnO@ZnS core-shell structure. The surface chemisty and band gap were investigated by XPS and UV-Vis spectra. The surface wetting properties were evaluated by photoluminescence, photocurrent respone and EIS analysis. Formation of the ZnO@ZnS core-shell structure and the incorporation of conductive Ni foam help to decrease the band gap and enhance the separation of photogenerated electron-hole pairs. The porous structure of the Ni foam facilitate the effective contact between the sacrificing agent and the immobilized photocatalyst. These factors contributed to improve the photocatalytic hydrogen production activity. The photocatalyst prepared with a sulfidation time for four hours exhibites the highest activity of 5860 μmol g-1 h-1, and still retaines 90% of hydrogen production activity. For the second part, dendritic PbS@CuS core-shell photocatalyst were synthesized by a two-step process, including the fabrication of a dendritic PbS nanomaterial as a core by hydrothermal method, followed by the formation of the CuS shell through an ion-exchange method. The morphology, surface chemisty, and crystal lattice properties of the core-shell nanomaterials were investigated. The effects of Copper(II) nitrate hydrate precursor concentration on the optical property, carrier separation, and the hydrogen production activity of the photocatalysts were studied. The hydrogen production activity of the photocatalyst prepared by 0.025M Copper(II) nitrate hydrate precursor reaches a maximum of 1736μmol g-1 h-1. PbS@CuS core-shell structure can effectively improve the photocatalytic activity. |
Databáze: | Networked Digital Library of Theses & Dissertations |
Externí odkaz: |