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.
MS in Nanotechnology
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(2018).Tuning the nature of defect states in black TiO2 nanostructures [Master's Thesis, the American University in Cairo]. AUC Knowledge Fountain.
Soliman, Moamen Mohamed. Tuning the nature of defect states in black TiO2 nanostructures. 2018. American University in Cairo, Master's Thesis. AUC Knowledge Fountain.