Carbon nitride photocatalysis : an investigation on the influence of morphology
department or school: Science, Irving K. Barber Faculty of (Okanagan)
department or school: Chemistry, Department of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Mitchell, Emma Louise
issued: 2021-12-16T19:51:29Z
issued: 2021
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: The development of reliable renewable energy sources is imperative for a sustainable future. To address this issue, the development of suitable photocatalysts that can produce clean renewable energy at a sustainable cost has become a rapidly expanding research area. Carbon nitride (CNx), an organic semiconductor, is a promising candidate for this role due to its easy synthesis, high stability and tunability. The potential of CNx has been highlighted with reports of highly efficient photocatalytic hydrogen production (quantum yields >50%) under sacrificial conditions. However, the efficiency remains limited for sustainable overall water splitting. To improve the efficiencies, modification of the material’s morphology has been pursued. However, research on the relationship between CNx morphology and photocatalytic efficiency has been inconclusive. Positive correlations as well as variances between CNx photocatalytic activity and surface area have been previously identified. To build a clear relationship between structure-photophysics-activity, different morphologies were prepared and studied. These were mesoporous (meso), macroporous (macro), SBA, and hollow sphere CNx. Progress towards synthesizing hollow sphere CNx was achieved, however, a reproducible synthesis has yet to be accomplished. The trend in photocatalytic hydrogen production of the successfully synthesized materials was as follows meso CNx, < Bulk CNx < SBA CNx < macro CNx. There were differences in the structural and electronic characterization, however, the trends were not consistent with the observed photocatalytic activity. Using Transient Absorption Spectroscopy (TAS), the normalized decay kinetics were found to be similar between all morphologies, indicating that changes in trap state distribution or electronic structure likely do not greatly impact the photocatalytic hydrogen evolution. A direct positive correlation between surface area and photocatalytic activity was observed. The largest increas…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/80461
note: Carbon Nitride Photocatalysis: An Investigation on the Influence of Morphology by Emma Louise Mitchell B.Sc., Queen’s University, 2019 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE COLLEGE OF GRADUATE STUDIES (Chemistry) THE UNIVERSITY OF BRITISH COLUMBIA (Okanagan) December 2021 © Emma Louise Mitchell, 2021 ii The following individuals certify that they have read, and recommend to the College of Graduate Studies for acceptance, a thesis/dissertation entitled: Carbon Nitride Photocatalysis: An Investigation on the Influence of Morphology submitted by Emma Louise Mitchell in partial fulfillment of the requirements of the degree of Master of Science. Dr. Robert Godin, Faculty of Science Supervisor Dr. Isaac Li, Faculty of Science Supervisory Committee Member Dr. David Jack, Faculty of Science Supervisory Committee Member Dr. Jonathan Holzman, School of Engineering University Examiner iii Abstract The development of reliable renewable energy sources is imperative for a sustainable future. To address this issue, the development of suitable photocatalysts that can produce clean renewable energy at a sustainable cost has become a rapidly expanding research area. Carbon nitride (CNx), an organic semiconductor, is a promising candidate for this role due to its easy synthesis, high stability and tunability. The potential of CNx has been highlighted with reports of highly efficient photocatalytic hydrogen production (quantum yields >50%) under sacrificial conditions. However, the efficiency remains limited for sustainable overall water splitting. To improve the efficiencies, modification of the material’s morphology has been pursued. However, research on the relationship between CNx morphology and photocatalytic efficiency has been inconclusive. Positive correlations as well as variances between CNx photocatalytic activity and surface area have been previously identified. To build a clear relationship between structur…
has type: Thesis/Dissertation
date issued: 2022-02
is shown at: 10.14288/1.0406077
language: eng
degree discipline: Chemistry
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Godin, Robert
type: Text
identifier URI: http://hdl.handle.net/2429/80461