A zinc titanate-based floatable composite for photocatalytic degradation of azophloxine

Zinc titanate was loaded onto expanded perlite (EP) by a sol-gel method to obtain a floatable ZnTiO₃/EP composite photocatalyst. The 28%ZnTiO₃/EP particles were well dispersed in water under gentle stirring, and they were also easily collected on the top of the treated water. ZnTiO₃ crystals in the ZnTiO₃ and 28%ZnTiO₃/EP samples were 43.5 and 38.5 nm in size, respectively. The bandgap energies of ZnTiO₃ and 28%ZnTiO₃/EP were determined to be 3.96 and 3.69 eV, respectively. EP contained large pores in the size of several micrometers, but it did not have small pores. The specific surface area of 28%ZnTiO₃/EP was determined to be 1.11 m²/g. The azophloxine degradation efficiencies of ZnTiO₃ and 28%ZnTiO₃/EP after 30 min of irradiation were determined to be 100 and 34.7%, respectively. A total of 94.8% of the azophloxine molecules were degraded on 28%ZnTiO₃/EP after 100 min of reaction.