Antireflective coatings of ZnO quantum dots and their photocatalytic activity
2012 (English)In: RSC Advances, ISSN 2046-2069, Vol. 2, no 27, 10298-10305 p.Article in journal (Refereed) Published
Thin films of ZnO quantum dots of different sizes have been deposited on conducting glass substrates. The films are transparent and work as antireflective coatings in the visible region. The negative absorption reaches down to -0.25 which represent a 77% increase in the transmitted light. Over a large part of the visible spectrum the increased transmittance is over 25%, and we demonstrate this to be a thin film effect. Under simulated solar illumination these films show a relatively high photocatalytic activity towards decomposition of methylene blue. The rate of photodecomposition depends on particle size and the smallest particles, which are less than 4 nm in diameter, show the highest quantum efficiency. We find the overall efficiency to be in the same order of magnitude to what's reported for commercial photocatalytic products like Degussa P25 and Pilkinton Active™, and maybe even somewhat better. We also demonstrate an increased hydrophilicity for the films under UV radiation. The photocatalytic oxidation of water into oxygen as a function of applied bias was measured in a three electrode system. The overall efficiency is small due to the high band gap but the internal quantum efficiency reaches over 10%.
Place, publisher, year, edition, pages
2012. Vol. 2, no 27, 10298-10305 p.
Anti reflective coatings, Applied bias, Conducting glass, Degussa P25, Different sizes, Film effects, Internal quantum efficiency, Large parts, Methylene Blue, Overall efficiency, Photo-catalytic, Photo-decomposition, Photocatalytic activities, Photocatalytic oxidations, Solar illumination, Three electrode-system, Transmitted light, Visible region, Visible spectra, ZnO quantum dots, Aromatic compounds, Coatings, Photocatalysis, Quantum efficiency, Semiconductor quantum dots, Substrates, Thin films, Ultraviolet radiation, Zinc oxide
Research subject Chemistry with specialization in Inorganic Chemistry
IdentifiersURN: urn:nbn:se:uu:diva-184913DOI: 10.1039/c2ra21566gISI: 000312138400028OAI: oai:DiVA.org:uu-184913DiVA: diva2:570577