標題: Microstructure evolution with composition ratio in self-assembled WO3-BiVO4 hetero nanostructures for water splitting
作者: Song, Haili
Li, Chao
Chien Nguyen Van
Liu, Heng-Jui
Qi, Ruijuan
Huang, Rong
Chu, Ying-Hao
Duan, Chun-Gang
材料科學與工程學系
Department of Materials Science and Engineering
關鍵字: BiVO4;microstructure;high resolution transmission electron microscopy;pseudo binary phase diagram;water splitting
公開日期: 1-七月-2017
摘要: A series of self-assembled WO3-BiVO4 nanostructured thin films with 17, 25, 50, 67, and 100 mol% WO3 were grown on the (001) yttria-stabilized zirconia (YSZ) substrate by pulsed laser deposition method. The microstructures including crystalline phases, epitaxial relationship, interface structures, and chemical composition distributions were investigated by a combination of various electron microscopy techniques including scanning electron microscopy, transmission electron microscopy, and X-ray energy dispersive spectroscopy. The monoclinic BiVO4 formed the matrix, in which WO3 nanopillars were embedded with specific epitaxial relationships. In BiVO4-rich sample, orthorhombic Bi2WO6 was formed. However, metastable hexagonal WO3 phase and orthorhombic WO3 phase coexisted in other composite samples. The thin amorphous layer at the film/substrate interface indicated that the mismatch strain between films and substrate is released. The hydrostatic tensile strain due to thermal expansion mismatch between BiVO4 and WO3 as well as the diffusion of Bi into the WO3 stabilized the metastable h-WO3. A WO3-BiVO4 pseudobinary phase diagram was proposed based on the magnitude of the thermal expansion mismatch and the distance of Bi diffusion, which can be applied to design the microstructures of WO3-BiVO4 heterojunctions and optimize their photoelectrochemical properties.
URI: http://dx.doi.org/10.1557/jmr.2017.250
http://hdl.handle.net/11536/145863
ISSN: 0884-2914
DOI: 10.1557/jmr.2017.250
期刊: JOURNAL OF MATERIALS RESEARCH
Volume: 32
起始頁: 2790
結束頁: 2799
顯示於類別:期刊論文