Effects of different surfactants on morphology of TiO2 and Zr-doped TiO2 nanoparticles and their applications in MB dye photocatalytic degradation

Abstract

In recent years, great attention has been paid to the synthesis of nano-size TiO2 due to its wide range of applications, particularly in the area of degradation of organic pollutants. In this study, different surfactants were used in synthesizing TiO2 and Zr-doped TiO2 nanoparticles. The effects of the surfactants’ types and concentrations on the morphology and size of the TiO2 nanoparticles were studied. The synthesized nanoparticles were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, and transmission electron microscopy. It was found that the TiO2 nanoparticles are a mixture of two anatase and rutile phases, whereas the surfactant-modified TiO2 nanoparticles have a dominant anatase phase. According to the SEM images, the synthesized nanoparticles’ morphologies depended not only on the type, but also on the concentration of the surfactants. The photocatalytic behavior of the nanoparticles on the degradation of methylene blue (MB) dye was evaluated. The maximum efficiency was achieved for the TiO2 nanoparticles synthesized using 0.08 molar surfactant Sodium bis(2-ethylhexyl)sulfosuccinate; reached 76% after 300 min of ultraviolet radiation. This indicated superior photocatalytic activity of this sample compared to all other synthesized nanoparticles, due to its uniform spherical morphology and particle sizes of 40–50 nm. For this sample, the effects of such parameters as catalyst amount and MB dye solution pH and temperature were optimized for its photocatalytic activity.