A novel magnetic heterojunction photocatalyst TiO₂/SrFe₁₂O₁₉: synthesis strategy, photocatalytic activity, and unprecedented migration mechanism of photoexcited charge carrier

ABSTRACT

A novel magnetic heterojunction photocatalyst TiO₂/SrFe₁₂O₁₉ was synthesized from self-made strontium carbonate and Tetra-n-butyl Titanate by ultrasound technique. Acting as magnetic substrate, multifunctional strontium ferrite (SrFe₁₂O₁₉) played an important role in the magnetic heterojunction photocatalyst system. On the one hand, as n-type semiconductors, SrFe₁₂O₁₉ was in contact with TiO₂, and a heterojunction was generated. On the other hand, as a hard-magnetic material SrFe₁₂O₁₉ can produce a stable magnetic field. This facilitates the recovery of photocatalyst from reaction solution with an extra magnet. More important, the stable magnetic field stemming from SrFe₁₂O₁₉ can promote separation between photo-induced electrons and holes and enhance the quantum efficiency for TiO₂. In this work, we proposed an unprecedented migration mechanism of photoexcited charge carriers. It is hope to provide new insight into photocatalytic mechanism for extending our understanding.

KEYWORDS:

• Magnetic photocatalyst
• TiO₂
• SrFe₁₂O₁₉
• heterojunction
• photocatalytic degradation
• migration mechanism

Acknowledgments

We would like to appreciate our associates, especially Weichao Zhang for their valuable contributions to our research program. We want to thank the financial support from Youth research talents′ growth support program of Yangtze Normal University and Chongqing Basic Science and Advanced Technology Research Program (CSTC2015jcyjBX0015). We gratefully acknowledge many important contributions from the researchers of all reports cited in our paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Youth research talents′ growth support program of Yangtze Normal University; Chongqing Basic Science and Advanced Technology Research Program; [CSTC2015jcyjBX0015].