Recyclable Magnetic Titania Nanocomposite from Ilmenite with Enhanced Photocatalytic Activity.

Tianjie Hong,Feifei Tao,Jun Mao,Mingxuan Lan

doi:10.3390/molecules22122044

Abstract

Using ilmenite as a raw material, iron was converted into Fe3O4 magnetic fluid, which further was combined with titanium filtrate by a solvothermal method. Finally Fe3O4/TiO2 nanocomposites with the uniform size of 100–200 nm were prepared. This approach uses rich, inexpensive ilmenite as a titanium and iron source, which effectively reduces the production cost. The crystal structure, chemical properties and morphologies of the products were characterized by SEM, TEM, XRD, FTIR, BET, UV-Vis, XPS and VSM. The novel photocatalyst composed of face-centered cubic Fe3O4 and body-centered tetragonal anatase–TiO2 exhibits a spherical shape with porous structures, superparamagnetic behavior and strong absorption in the visible light range. Using the degradation reaction of Rhodamine B (RhB) to evaluate the photocatalytic performance, the results suggest that Fe3O4/TiO2 nanocomposites exhibit excellent photocatalytic activities and stability under visible light and solar light. Moreover, the magnetic titania nanocomposites displayed good magnetic response and were recoverable over several cycles. Based on the trapping experiments, the main active species in the photocatalytic reaction were confirmed and the possible photocatalytic mechanism of RhB with magnetic titania was proposed. The enhanced photocatalytic activity and stability, combined with excellent magnetic recoverability, make the prepared nanocomposite a potential candidate in wastewater purification.

Highlights

With the rapid development of human society, environmental pollution and energy shortages have become the two major problems which need more attention to
Pure TiO2 can be activated only by ultraviolet light which is less than 5% of the total solar energy reaching earth due to its wide band gap (3.0 to ~3.2 eV) [9], and exhibits a low quantum efficiency due to the easy recombination of photogenerated electrons and holes [10]
In order to improve the photocatalytic activity of TiO2, nanostructured TiO2 is often expected to exhibit outstanding photocatalytic performance, owing to their larger specific surface area and good dispersion in aqueous solutions [11]

Summary

Introduction

With the rapid development of human society, environmental pollution and energy shortages have become the two major problems which need more attention to. The use of photocatalysis technology, applying solar energy efficiently to achieve photocatalytic degradation of organic pollutants [1,2,3,4], is an effective way to solve the above stated problems. Pure TiO2 can be activated only by ultraviolet light which is less than 5% of the total solar energy reaching earth due to its wide band gap (3.0 to ~3.2 eV) [9], and exhibits a low quantum efficiency due to the easy recombination of photogenerated electrons and holes [10]. How to separate and recover nano-TiO2 , and improve the visible-light-driven nano-TiO2 , have been research hotspots [13,14]

Methods

Results

Conclusion