AUTHOR=Yin Hang , Zhao YuLing , Hua Qingsong , Zhang Jianmin , Zhang Yuansai , Xu Xijin , Long Yunze , Tang Jie , Wang Fengyun 

TITLE=Controlled Synthesis of Hollow α-Fe2O3 Microspheres Assembled With Ionic Liquid for Enhanced Visible-Light Photocatalytic Activity

JOURNAL=Frontiers in Chemistry

VOLUME=7

YEAR=2019

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2019.00058

DOI=10.3389/fchem.2019.00058

ISSN=2296-2646

ABSTRACT=<p>Porous self-assembled α-Fe<sub>2</sub>O<sub>3</sub> hollow microspheres were fabricated via an ionic liquid-assisted solvothermal reaction and sequential calcinations. The concentration of the ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate [C<sub>4</sub>Mim]BF<sub>4</sub>) was found to play a crucial role in the control of these α-Fe<sub>2</sub>O<sub>3</sub> hollow structures. Trace amounts ionic liquid was used as the soft template to synthesize α-Fe<sub>2</sub>O<sub>3</sub> hollow spheres with a large specific surface (up to 220 m<sup>2</sup>/g). Based on time-dependent experiments, the proposed formation mechanisms were presented. Under UV light irradiation, the as-synthesized α-Fe<sub>2</sub>O<sub>3</sub> hollow spheres exhibited excellent photocatalysis in Rhodamine B (RhB) photodegradation and the rate constant was 2–3 times higher than α-Fe<sub>2</sub>O<sub>3</sub> particles. The magnetic properties of α-Fe<sub>2</sub>O<sub>3</sub> hollow structures were found to be closely associated with the shape anisotropy.</p>