Titania nanoparticle-loaded mesoporous silica synthesized through layer-by-layer assembly for the photodegradation of sodium dodecylbenzenesulfonate

Abstract

Titania nanoparticle-loaded mesoporous silica has been studied as a promising photocatalytic material for the removal of organic pollutants. However, the synthesis methods and photodegradation properties have not yet been optimized. In this study, titania-loaded mesoporous silica (SBA-15) was synthesized using a layer-by-layer (LbL) assembly method. The photodegradation properties were compared to those of materials produced by the conventional synthesis method based on sol-gel reactions for the decomposition of sodium dodecylbenzylsulfate. The LbL-synthesized samples exhibit enhanced photocatalytic performance compared to that of the sol-gel samples. The total degradation amount after 5 h of UV irradiation increased by approximately 63%-108%, and the apparent first-order rate constant increased by a factor of approximately 2.4. They also presented higher photocatalytic performances during reusability tests comparing other samples. The titania nanoparticles were mainly localized on the external surface of the silica in the LbL-synthesized samples, which is more beneficial for photodegradation than infiltrated inside the mesopores in the sol-gel samples. The results of this study can be of use for the design of photocatalytic nanomaterials for environmental applications.