Facile Synthesis of Flower-Like TiO2-Based Composite for Adsorption–Photocatalytic Degradation of High-Chroma Methylene Blue

Abstract

A flower-like TiO2-based composite (denoted as Zn-Ti-6) was prepared using a flower-like zinc oxide template for adsorption–photocatalytic degradation of high-chroma methylene blue. The reaction took place in an alkaline environment following hydrochloric acid treatment to remove the template and form TiO2-based composite. Sodium hydroxide played both roles of morphology-directing agent and reactive etchant. The possible mechanism for the formation of flower-like Zn-Ti-6 was proposed. The adsorption and photocatalytic degradation behavior of Zn-Ti-6 on methylene blue (MB) removal was also investigated. The results revealed that Zn-Ti-6 showed better adsorption and photocatalytic degradation performance than TiO2 nanoparticles owing to its much larger specific surface area, more abundant hydroxyls, and lower photoluminescence intensity. The adsorption and photocatalytic degradation data of Zn-Ti-6 were well fitted to the pseudo-second-order and pseudo-first-order kinetics models, respectively. The excellent adsorption performance of Zn-Ti-6 is largely beneficial to the subsequent photocatalytic degradation performance for high-chroma wastewater treatment. Overall, this study contributes a facile fabrication strategy for flower-like TiO2-based composite to achieve the adsorption–photocatalytic degradation of high-chroma wastewater.