Abstract

Black TiO2 is being widely investigated due to its superior optical activity. Herein, the limitations of the hydrogenation process are unraveled by exploiting the fundamental tradeoffs affecting the overall efficiency of the water splitting process. Different reduction rates are applied to sub-100 nm TiO2 highly efficient short nanotubes. X-ray photoelectron spectroscopy reveals changes in the stoichiometry of TiO2 with the reduction rate. UV-Vis and Raman spectra reveal that high reduction rates promote the formation of the rutile phase in TiO2, which is inactive towards water splitting. The electrochemical analysis discloses that low reduction rates induce higher concentration of localized electronic defect states that hinder the water splitting performance. Finally, incident photon-to-current conversion efficiency (IPCE) points out to the optimum reduction rate that attains relatively lower defects concentration as well as lower rutile content, thereby achieving the highest conversion efficiency.

Department

Nanotechnology Program

Degree Name

MS in Nanotechnology

Date of Award

2-1-2018

Online Submission Date

August 2017

First Advisor

Allam, Nageh

Committee Member 1

AlFiky, Mohamed

Committee Member 2

Hegazy, Aiat

Document Type

Thesis

Extent

74 p.

Rights

The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy.

IRB

Approval has been obtained for this item

Comments

Research Grant, The American University in Cairo

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