Synthesis of hollow sphere structured TiO2 loaded with Ag2O and its photocatalytic activity

Abstract

Owing to its high stability and catalytic activity, TiO₂ has been widely used as a photocatalyst where its photocatalytic performance can be significantly improved by microstructure regulation and semiconductor loading. Herein, hollow TiO₂ spheres were prepared using phenolic resin as the template and the Ag₂O nanoparticles were loaded onto the TiO₂ spheres by the wet precipitation method. The physicochemical characteristics demonstrated the successful preparation of the Ag₂O/TiO₂ nanocomposites. Various AgNO₃ concentrations were employed and the results revealed that increasing the loaded Ag amount from 16.24% to 62.25% resulted in an increase in the corresponding Ti : Ag ratio in the Ag₂O/TiO₂ nanocomposites from 1 : 0.79 to 1 : 10.48, respectively. The bandgap of the synthesized Ag₂O/TiO₂ nanocomposites was in the range of 1.61–1.75 eV. The photodegradation rate of phenol in the presence of Ag₂O/TiO₂ as the catalyst reached 95.2% under UV light irradiation which was much higher than that under visible light irradiation. This improvement can be attributed to the synergistic effect of Ag₂O and TiO₂. The loading of Ag₂O induced more electron traps on the surface of the Ag₂O/TiO₂ composites, thereby increasing the mobility of the carrier and thus improving the catalytic activity.