Influence of Surfactant on the Morphology and Photocatalytic Activity of Anatase TiO2 by Solvothermal Synthesis

Abstract

Highly photocatalytically active anatase TiO2 were synthesized by a solvothermal method using tetrabutyl titanate (TBT), citric acid, and ethanol as row material. The morphology and photocatalytic activity of titanium oxide have changed significantly with the presence of surfactants, such as cetyltrimethylammonium bromide (CTAB), sodium dodecylbenzenesulfonate (SDBS), and diethanolamine (DEA). Scanning electron microscope and X-ray powder diffraction results show that the synthesized products are anatase TiO2 spherical particles with a micronanostructure. The crystal type of TiO2 has no obvious change with the addition of different surfactants, but the morphology, size, and dispersion of the TiO2 particles have changed to some extent. Among the three surfactants, CTAB is beneficial to reduce TiO2 particle size and improve TiO2 dispersion and agglomeration. DEA is favor to self-assembly the nanocrystals into spherical particles. Degradation of methyl orange photocatalyzed by TiO2 prepared with CTAB as surfactant reaches 95.4% under ultraviolet light for 100 min. After five recycles, the catalyst did not exhibit significant loss of photocatalytic activity, confirming that the photocatalyst is essentially stable. This work indicates that the surfactant-assisted solvothermal method is an effective approach to improve the structure, morphology, and photocatalytic performance of TiO2. Moreover, the surfactants with various types can interact with the precursors of TiO2 in different ways.