Non-Stacked γ-Fe2O3/C@TiO2 Double-Layer Hollow Nanoparticles for Enhanced Photocatalytic Applications under Visible Light.

Xun Sun,Hengli Qian,Lijun Zhao,Erhong Duan,Junjie Shi,Jianrui Niu,Xiao Yan,Libo Sun,Zifan Wang,Huijuan Su

doi:10.3390/nano12020201

Abstract

Herein, a non-stacked γ-Fe2O3/C@TiO2 double-layer hollow nano photocatalyst has been developed with ultrathin nanosheets-assembled double shells for photodegradation phenol. High catalytic performance was found that the phenol could be completely degraded in 135 min under visible light, due to the moderate band edge position (VB at 0.59 eV and CB at −0.66 eV) of the non-stacked γ-Fe2O3/C@TiO2, which can expand the excitation wavelength range into the visible light region and produce a high concentration of free radicals (such as ·OH, ·O2−, holes). Furthermore, the interior of the hollow composite γ-Fe2O3 is responsible for charge generation, and the carbon matrix facilitates charge transfer to the external TiO2 shell. This overlap improved the selection/utilization efficiency, while the unique non-stacked double-layered structure inhibited initial charge recombination over the photocatalysts. This work provides new approaches for photocatalytic applications with γ-Fe2O3/C-based materials.

Highlights

Phenol containing wastewater is produced in many industries, such as pharmaceuticals, polymer, dye, etc. [1]
This study demonstrates a facile route to synthesize non-stacked γ-Fe2 O3 /C@TiO2 double-layer hollow nanoparticles
We found that two-step charge generation and charge transfer were matched and synergistically enhanced in the non-stacked γ-Fe2 O3 /C@TiO2 double-layer hollow nanoparticles, which significantly improved the photodegradation of phenol

Summary

Introduction

Phenol containing wastewater is produced in many industries, such as pharmaceuticals, polymer, dye, etc. [1]. Photocatalysis is a simple technology among water treatment technologies [5,6,7], owing to its high mineralization and sturdy treatment efficiency [8,9]. Two significant problems need to be solved: The low specific surface area of TiO2 (50 m2 /g for P25, TiO2 with a mixed rutile phase, and anatase phase with an average particle size of 25 nm) confines its adsorption capacity for pollutant molecules. It has a wide energy gap and is challenging to utilize visible light

Methods

Results

Conclusion