Nanoparticles with non-equilibrium structures synthesized by physical ways

Xia, Yu ORCID: https://orcid.org/0000-0002-0728-9201 (2023). Nanoparticles with non-equilibrium structures synthesized by physical ways. University of Birmingham. Ph.D.

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Abstract

Synthesizing nanoparticles with nonequilibrium structures and shapes is full of significance not only due to the excellent catalytic performance, but also because of the role on the understanding of crystal growth. This work focuses on the nanoparticle preparation through physical routes and the structural characterisation using scanning transmission electron microscopy (STEM). Magnetron-sputtering gas condensation method was employed to prepare population-tunable platinum (Pt) tetrahedral and octahedral nanoparticles with mass-selection. The growth pathway of tetrahedral Pt nanoparticles was simulated based on the experimental conditions and the STEM images. The same strategy was employed to prepare nickel-platinum (Ni-Pt) nanoparticles from alloys to core-shells by tuning preparation conditions. In the presence of Ni atoms during the growth stage, Ni-Pt nanoparticles formed with icosahedral and decahedral structures, which show robust structural stability observed by in-situ heating. Joule heating is a novel nanoparticle synthesis, which was utilized to fabricate metal nanoparticles and metallic phosphides within second in this thesis. Thanks to the ultrafast heating and cooling rates of the Joule heating synthesis, both stacking faults and metastable structures were remained in the as-prepared nanoparticles. Pt doped ruthenium nanoparticles with a face-centered cubic structure prepared using flash Joule heating was demonstrated for the application of electrocatalytic hydrogen evolution reaction with ultralow overpotentials and small Tafel slopes. The synthesis techniques shown in this thesis have implications for catalysts preparation.

Type of Work:	Thesis (Doctorates > Ph.D.)
Award Type:	Doctorates > Ph.D.
Supervisor(s):	Supervisor(s) Email ORCID Theis, Wolfgang UNSPECIFIED UNSPECIFIED Guo, Quanmin UNSPECIFIED UNSPECIFIED Xiangling, Hsing-Lin UNSPECIFIED UNSPECIFIED
Licence:	All rights reserved
College/Faculty:	Colleges (2008 onwards) > College of Engineering & Physical Sciences
School or Department:	School of Physics and Astronomy
Funders:	Other
Other Funders:	Southern University of Science and Technology
Subjects:	Q Science > QC Physics
URI:	http://etheses.bham.ac.uk/id/eprint/13749

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