Deposition of multifunctional TiO2 and ZnO top-protective coatings for CSP application

Houda Ennaceri, Darja Erfurt, Lan Wang, Tristan Köhler, Abdelhafed Taleb, Asmae Khaldoun, Abdallah El Kenz, Abdelilah Benyoussef, Ahmed Ennaoui

Research output: Contribution to journalArticle

11 Citations (Scopus)


In this work, high quality, transparent multifunctional and smart anatase TiO2 and wurtzite ZnO top protective coatings used for CSP silver-based first-surface thick glass mirrors are studied. The TiO2 and ZnO top-coatings are deposited using chemical spray pyrolysis technique which conserves a very good specular reflectance of the mirrors (94% reflectance in the Near Infrared range). The photocatalytic activity of the prepared top-coatings is evaluated using the methylene blue dye (MB) as a model molecule, and the highest activity is observed for ZnO top-coating, with a degradation efficiency of 42%. Moreover, the effect of post-annealing treatment on the photocatalytic degradation of the top-coatings is pointed out, and is explained in terms of crystallinity and surface morphology. The increase of the photocatalytic activity can be achieved by increasing surface roughness, which is a conflicting requirement with optical transparency needed for concentrated solar power (CSP) top-coating application. Furthermore, it is pointed out that TiO2 and ZnO top protective thin films exhibit a photo-induced switching of their wetting properties only after 30 min of UV exposure, and their usability as multifunctional top-protective layers for CSP application is discussed.

Original languageEnglish
Pages (from-to)103-113
Number of pages11
JournalSurface and Coatings Technology
Publication statusPublished - 25 Jul 2016
Externally publishedYes



  • Concentrated solar power
  • Multifunctional coating
  • Photocaytalysis
  • Smart coating
  • Specular reflectance
  • Thin film
  • TiO
  • ZnO

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Materials Chemistry
  • Surfaces, Coatings and Films
  • Surfaces and Interfaces

Cite this

Ennaceri, H., Erfurt, D., Wang, L., Köhler, T., Taleb, A., Khaldoun, A., El Kenz, A., Benyoussef, A., & Ennaoui, A. (2016). Deposition of multifunctional TiO2 and ZnO top-protective coatings for CSP application. Surface and Coatings Technology, 298, 103-113.