Honors College Thesis
 

Investigation of MoS2 with Ambient Pressure X-ray Photoelectron Spectroscopy

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/honors_college_theses/9w032929p

Descriptions

Attribute NameValues
Creator
Abstract
  • Molybdenum disulfide (MoS2) has potential applications as a low-cost catalyst for the hydrogen evolution reaction (HER). Defects on MoS2, such as edge sites and sulfur vacancies, are known to be the major active sites for HER. Controlling the formation of these defects allows for the enhancement in reactivity of MoS2 and other 2D materials. In this study, we have characterized the surface reactivity of bulk MoS2 samples using ambient pressure X-ray photoelectron spectroscopy (APXPS). Samples were exposed to 1 mbar of H2O vapor at temperatures ranging from 300-600 K. The APXPS Mo 3d, S 2p, and O 1s core levels for the as exfoliated surface showed no significant changes under all reaction temperatures due to the inert nature of the pristine MoS2 surface. To improve surface reactivity and activate the basal plane of MoS2 we have utilized Ar+ sputtering to form well controlled defect densities at the surface. The APXPS Mo 3d, S 2p, and O 1s core levels for the defective MoSx (x = 1.6, 1.2) surface showed the formation of MoO3 and MoOS at temperatures of 400 K and above. We have found that surface reactivity of MoS2 is strongly dependent on temperature and defect densities.
License
Resource Type
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Non-Academic Affiliation
Rights Statement
Funding Statement (additional comments about funding)
  • Acquisition of the Ambient-Pressure X-ray Photoelectron Spectroscopy/Ambient-Pressure Scanning Tunneling Microscopy system was supported by the National Science Foundation-Major Research Instrumentation program (grant DMR-1429765), the M. J. Murdock Charitable Trust, Oregon BEST, Oregon Nanoscience and Microtechnologies Institute, and Oregon State University.
Publisher
Peer Reviewed
Language

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details DardzinskiDerekP2020.pdf 2020-06-02 Public Download