Preparation of surfactant-modified ZnTiO3–TiO2 nanostructures and their photocatalytic properties under sunlight irradiation

Abstract

A series of ZnTiO3–TiO2 mixed oxide nanoparticles were successfully synthesized using a simple sol–gel technique and modified with hexadecyl trimethyl ammoniumbromide, sodium dodecyl sulfate, N-cetyl-NNN-trimethyl ammonium bromide as surfactant. The samples were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Fourier transform infrared (FT-IR), diffuse reflectance spectra (DRS) and scanning electron microscopy techniques (SEM). The photocatalytic activity of samples was investigated by degradation of 4-chlorophenol in water under sunlight and ultraviolet irradiation. The sodium dodecyl sulfate-assisted sample was found to exhibit much higher photocatalytic activity than the other surfactants. The highest photocatalytic efficiency (100 %) was obtained with ZnTi-sodium dodecyl sulfate sample in 60 min. Hexagonal form of ZnTiO3 is found to be more effective for photodegradation. Meanwhile, the processing parameters such as the light source and the amount of surfactant play an important role in tuning the photocatalytic activity. The enhancement of photocatalytic activity for ZnTi-sodium dodecyl sulfate may be attributed to its small particle size, the presence of more surface OH groups, lower band gap energy than no surfactant included sample and the presence of more hexagonal ZnTiO3 phase in the morphology.