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

Mengqi Tian,Runjun Sun,Jingjing Wang,Lianbi Li,Mu Yao

doi:10.3390/catal11040515

Mengqi Tian, Runjun Sun + Show 3 more

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https://doi.org/10.3390/catal11040515

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Journal: Catalysts	Publication Date: Apr 20, 2021
Citations: 4	License type: CC BY 4.0

Affiliation: Soochow University, Xi'an Polytechnic University

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.

Highlights

With the rapid development of the textile industry, the resultant organic water pollutions pose a long-term threat to the environment and human health [1,2]
Zn-Ti-6 exhibited better adsorption and photocatalytic degradation capacity toward methylene blue (MB) solution than P25, which was attributed to Zn-Ti-6 having a larger specific surface area, more abundant hydroxyls, and lower photoluminescence intensity than P25
For high-chroma wastewater, excellent adsorption performance is largely beneficial to the subsequent photocatalytic degradation performance

Summary

Introduction

With the rapid development of the textile industry, the resultant organic water pollutions pose a long-term threat to the environment and human health [1,2]. The wastewater from textile dyeing containing high concentrations of dyestuffs, such as methylene blue (MB), is one of the most harmful industrial effluents [3,4]. A large number of photocatalytic degradation technologies have been developed to remove the dye residues from wastewater. The photocatalytic degradation technology performs poorly, especially for high-chroma wastewater. The reason is that the poor light transmittance of high-chroma wastewater suppresses the photocatalyst performances [5,6,7]. Adsorption technology has been widely applied in the field of wastewater treatment for its simple operation and generality [8]. Adsorption alone cannot degrade toxic substances or dyes into non-toxic and pollution-free H2O and CO2, etc. An adsorption– photocatalytic degradation strategy has been proposed by many researchers [11,12,13]

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