|Title:||Cuprous oxide-based cathodes for photocatalytic water splitting||Other Titles:||Kupfer(I)oxid-basierte Kathoden zur photokatalytischen Wasserspaltung||Language:||English||Authors:||Kupka, Jana Katharina||Qualification level:||Diploma||Advisor:||Weil, Matthias||Issue Date:||2021||Citation:||
Kupka, J. K. (2021). Cuprous oxide-based cathodes for photocatalytic water splitting [Diploma Thesis, Technische Universität Wien]. reposiTUm. https://doi.org/10.34726/hss.2021.83289
|Number of Pages:||84||Qualification level:||Diploma||Abstract:||
Photoelectrochemical water splitting appears to be a promising replacement for fossil fuels as an easily accessible source of energy. Cuprous oxide (Cu2O) seems to be an ideal p-type absorber semiconductor for a photoelectrochemical (PEC) cell, providing a suitable band gap to perform hydrolysis under visible light. The main challenge with this material is its strong tendency towards photocorrosion, causing instabilities in creating photocurrents. Through optimization of the applied voltage in electrochemical deposition (ECD) of Cu2O, this problem is being explored. Also, modifying additional layers, like the choice of material for an optimal p-n-junction or the layer thicknesses deposited via sputtering, are being investigated. Furthermore, the cell’s testing environment (inert gas purging, electrolyte composition and pH value) is being studied. The testing is carried out under chopped 1.5 AM one sun illumination in an acidic environment with a three-electrode-setup. By increasing the applied potential for the nucleation process for ECD, a much more compact and uniform absorber layer has been grown. Additional Zn(O,S) as a buffer layer and niobium doped titanium dioxide for passivation fills remaining holes in the absorber layer, provides a p- n-junction for efficient charge separation and protects Cu2O from corrosion. An electrolyte environment with a pH value of 3 has proven to be most effective in creating a photocurrent. This way, unprotected cells have shown to deliver current densities of up to 2.35 mA/cm2, which equals a solar-to-hydrogen (STH) efficiency of 2.9%. Cells with additional window layers provided stable photocurrent of 1.1 mA/cm2 even without using a photocatalyst, which makes this set-up a promising candidate for future PEC cells.
|Keywords:||Kupfer(I) oxid; Photokatalysator; Kathodenmaterial; Wasserspaltung
Copper(I) oxide; photocatalyst; cathode material; water splitting
|DOI:||10.34726/hss.2021.83289||Library ID:||AC16384844||Organisation:||E164 - Institut für Chemische Technologien und Analytik||Publication Type:||Thesis
|Appears in Collections:||Thesis|
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