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Prepartion Of Bi2O3@Bi2S3and CdO@CdS Core-Shell Structured Macro/Nano-Semiconductor Materials And Their Photoelectrochemical Properties

Posted on:2013-03-27Degree:MasterType:Thesis
Country:ChinaCandidate:F A LiuFull Text:PDF
GTID:2231330374469821Subject:Physical chemistry
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Macro/nano-scale semiconductor photoelectric materials with core-shell structure have been attracted wide attention due to their unique physical and chemical properties and applications in photoelectrochemical solar cells, optoelectronics, optics, biology and medicine, and so on. The type-Ⅱ core-shell nanostructures have obtained considerable development in recent years as a result of the unique band edge alignment. In this work, we studied the preparation of Bi2O3@Bi2S3and CdO@CdS type-II core-shell semiconductors and their photoelectrochemical properties. The main contents are as follows:(1) Thin films of type-Ⅱ Bi2O3@Bi2S3core-shell nanoparticles (NPs) have been assembled on fluorine doped tin oxide (FTO) coated conducting glass substrates via a facile new route. It contains three steps: electrochemical dispersion of a Bi electrode into Bi NPs collected with the FTO substrate, thermal treatment of the assembled thin film of Bi NPs on FTO into Bi2O3NPs, and then surface sulfurization of the Bi2O3NPs. The Bi2O3@Bi2S3core-shell structure was confirmed by combined analysis of XRD and Raman spectroscopy. The influence of collection time and surface sulfurization time on the photoelectrochemical performance was investigated. The prepared Bi2O3@Bi2S3core-shell film displayed better photoelectrochemical performance and photoresponse than that of respective films of Bi2S3NPs and Bi2O3NPs and the reason was discussed.(2) Dendritic thin films of type-Ⅱ Bi2O3@Bi2S3core-shell semiconductors have been prepared on the FTO through three steps, including electrodepositon of dendritic Bi film, oxidation by thermal treatment and surface sulfurization of the Bi2O3dendrite. The Bi2O3@Bi2S3core-shell structure was confirmed by combined analysis of XRD and XPS. The influence of electrodepositon time and surface sulfurization time on the photoelectrochemical performance was investigated. The prepared type Ⅱ Bi2O3@Bi2S3core-shell film displayed better photoelectrochemical performance than that of respective Bi2S3film and Bi2O3film and the reason was discussed.(3) Thin films of type-Ⅱ CdO@CdS core-shell macro/nanoparticles were obtained on FTO through three steps:electrodepositon of Cd particles, oxidation by thermal treatment and surface sulfurization of the CdO particles. The CdO@CdS core-shell structure was confirmed by combined analysis of XRD and XPS. The influence of electrodepositon time and surface sulfurization time on the photoelectrochemical performance was investigated. The prepared CdO@CdS core-shell film displayed better photoelectrochemical performance than that of respective CdO and CdS films, and the reason was discussed. The photovoltage properties of CdO@CdS core-shell films in defferent electrolytes have also been studied.
Keywords/Search Tags:semiconductor, type-Ⅱ core-shell structure, photoelectrochemistry, photoresponse, oxide, sulfide, eletrodeposition
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