Paving the Way for A Sustainable and Efficient SiO2/TiO2 Photocatalytic Composite

• Published in: Environments (Basel, Switzerland) Vol. 6; no. 8; p. 87
• Main Authors: Pierpaoli, Mattia, Zheng, Xu, Bondarenko, Vladimir, Fava, Gabriele, Ruello, Maria Letizia
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.08.2019
• Subjects: Adsorption; Catalytic activity; Composite materials; de-polluting; Environmental impact; Holes (electron deficiencies); Humidity; Hydroxyl groups; Impact analysis; MEK; Methods; Nitrogen; NOx; Photocatalysis; Pollutants; Pore size; Production costs; Recombination; Shavings; Silica; Silicon dioxide; SiO2/TiO2 composite; Sustainability; Titanium; Titanium dioxide; Waste materials
• ISSN: 2076-3298; 2076-3298
• DOI: 10.3390/environments6080087

Although photocatalysis is an extraordinary and tremendously explored topic, there is a need to find new ways to encourage the production of composite materials that are economical, efficient and with limited environmental impact. Nanocatalysts may benefit from appropriate support material for many reasons. In this study, TiO2 was deposited on SiO2, so that the silica not only provides the macroscopic structure on which the TiO2 is formed, but it positively affects the photocatalytic activity as well. This is because of the greater specific surface area which favors the adsorption of pollutants near the photocatalyst, the higher amount of surface-adsorbed water and hydroxyl groups and the inhibition of the photogenerated electron-hole recombination. The choice of preparing the Ti-precursor starting from titanium shavings and to directly deposit TiO2 on micrometric-sized silica by a simple hydrothermal method highlights the process sustainability. The results showed that it is possible to produce a photocatalytic composite from secondary materials, exhibiting excellent photocatalytic properties, comparable to the pristine one, and opening the possibility for large-scale production.