Gas phase generation and deposition of size-selected metal clusters

Abdela, Ahmed (2014). Gas phase generation and deposition of size-selected metal clusters. University of Birmingham. Ph.D.

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Abstract

This thesis presents modifications to and optimisations of a cluster beam source, one application being the generation of large area catalysis samples. A major modification to the cluster source also enabled coating of clusters in a new way. The impact of Pd\(_5\)\(_6\)\(_1\), Pd\(_5\)\(_5\)and Pd\(_4\) clusters (1, 1.5 and 1 keV) on a thin material film evaporated onto a solid argon matrix led to deposition of large, 5-40 nm diameter, irregularly shaped particles. Furthermore, Pd\(_9\)\(_2\)\(_3\) and Pd\(_2\)\(_0\)\(_0\)\(_0\) clusters, with both 0.5 and 1.5 keV impact energies, have been coated in-flight by impact on the thin film/solid matrix, as verified from the increase in diameters of the deposited particles and the detection of Pd signal by EELS.
MoS\(_2\) nano pillar catalyst samples were etched using size-selected metal etch masks. Catalyst samples of ordered MoS\(_2\) nano pillars were fabricated using NSL and a novel way to apply nano spheres was developed. Different etch recipes were used to obtain nano pillars with different diameters and heights; these recipes were also applied to reference MoS\(_2\) samples without etch masks. Generally, the reference catalyst samples, with their roughened surfaces, showed higher HER activity than their corresponding ordered MoS2 nano pillar catalyst samples.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):