Sol-gel hot injection synthesis of ZnO nanoparticles into a porous silica matrix and reaction mechanism

Ahmed Barhoum, Guy Van Assche, Hubert Rahier, Manuel Fleisch, Sara Bals, Marie-Paule Delplancked, Frederic Leroux, Detlef Bahnemann

Research output: Contribution to journalArticle

32 Citations (Scopus)


Despite the enormous interest in the properties and applications of porous silica matrix, only a few attempts have been reported to deposit metal and metal oxide nanoparticles (NPs) inside the porous silica matrix. We report a simple approach (i.e. sol-gel hot injection) for insitu synthesis of ZnO NPs inside a porous silica matrix. Control of the Zn:Si molar ratio, reaction temperature, pH value, and annealing temperature permits formation of ZnO NPs (≤ 10 nm) inside a porous silica particles, without additives or organic solvents. Results revealed that a solid state reaction inside the ZnO/SiO2 nanocomposites occurs with increasing the annealing temperature. The reaction of ZnO NPs with SiO2 matrix was insignificant up to approximately 500 °C. However, ZnO NPs react strongly with the silica matrix when the nanocomposites are annealed at temperatures above 700 °C. Extensive annealing of the ZnO/SiO2 nanocomposite at 900 °C yields 3D structures made of 500 nm rod-like, 5-7 µm tube-like and 3-5 µm needle-like Zn2SiO4 crystals. A possible mechanism for forming ZnO NPs inside porous silica matrix and phase transformation of the ZnO/SiO2 nanocomposites into 3D architectures of Zn2SiO4 are carefully discussed.
Original languageEnglish
Pages (from-to)270-276
Number of pages7
JournalMaterials & Design
Publication statusPublished - 5 Apr 2017


  • Architectured nanostructures
  • Nanocomposite
  • Porous silica matrix
  • Sol-gel hot injection
  • Zinc oxide nanoparticles
  • Zinc silicate

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