Exfoliation of conductive layered materials in solutions

dc.contributor.authorYang, Sheng
dc.date.accessioned2018-04-12T12:53:54Z
dc.date.available2018-04-12T14:53:54Z
dc.date.issued2018
dc.description.abstractThis PhD thesis focuses on the scalable exfoliation of van der Waals crystals (e.g. graphite, black phosphorus) into high-quality two-dimensional flakes by means of electrochemical engineering in solutions. In contrast to conventional physical or chemical exfoliation strategies by which the production of these materials has to compromise between scalability and quality, in this thesis, the electrolytic parameters including ionic species, working electrodes, working bias and cell configuration were systematically studied and carefully considered to enable low structural damage as well as high throughput capability of the exfoliated materials. In chapter 2, we demonstrate an efficient approach using reducing agents or radical scavengers during anodic exfoliation process, to avoid the attack of reactive oxygen-containing radicals (e.g. ·OH and ·O·) from water oxidation, which has been considered as the major source for the oxide groups on exfoliated graphene. In chapter 3, we present a novel cell structure with two graphite working electrodes (i.e. anode and cathode) that can be exfoliated simultaneously, by taking advantage of alternating currents. The polarity switch of working bias promotes not only fast exfoliation rate but also high graphene quality. In addition, the potential applications such as printable inks, flexible supercapacitors, lithium ion batteries were explored to evaluate the features of high-quality graphene. Inspired by graphite exfoliation, in chapter 4, we manage to produce large-sized defect-free, few-layer black phosphorus (BP) flakes through the cathodic exfoliation of bulk crystal in organic electrolytes. The exfoliated flakes exhibit excellent hole mobility and remarkable on/off ratio, well comparable with those of mechanically exfoliated BP flakes. This simple and scalable method shows great potential in the future development of BP-based technologies. At last, the challenges and opportunities in the exfoliation of layered conductive or semiconducting materials have been summarized in chapter 5, as the guidelines for the future studies.en_GB
dc.identifier.doihttp://doi.org/10.25358/openscience-2651
dc.identifier.urihttps://openscience.ub.uni-mainz.de/handle/20.500.12030/2653
dc.identifier.urnurn:nbn:de:hebis:77-diss-1000019558
dc.language.isoeng
dc.rightsInC-1.0de_DE
dc.rights.urihttps://rightsstatements.org/vocab/InC/1.0/
dc.subject.ddc540 Chemiede_DE
dc.subject.ddc540 Chemistry and allied sciencesen_GB
dc.titleExfoliation of conductive layered materials in solutionsen_GB
dc.typeDissertationde_DE
jgu.description.extent143 Seiten
jgu.organisation.departmentFB 09 Chemie, Pharmazie u. Geowissensch.
jgu.organisation.nameJohannes Gutenberg-Universität Mainz
jgu.organisation.number7950
jgu.organisation.placeMainz
jgu.organisation.rorhttps://ror.org/023b0x485
jgu.organisation.year2018
jgu.rights.accessrightsopenAccess
jgu.subject.ddccode540
jgu.type.dinitypePhDThesis
jgu.type.resourceText
jgu.type.versionOriginal worken_GB
opus.date.accessioned2018-04-12T12:53:54Z
opus.date.available2018-04-12T14:53:54
opus.date.modified2018-04-23T11:39:36Z
opus.identifier.opusid100001955
opus.institute.number0905
opus.metadataonlyfalse
opus.organisation.stringFB 09: Chemie, Pharmazie und Geowissenschaften: Institut für Organische Chemiede_DE
opus.subject.dfgcode00-000
opus.type.contenttypeDissertationde_DE
opus.type.contenttypeDissertationen_GB

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