Insight of the Influence of Magnetic-Field Direction on Magneto-Plasmonic Interfaces for Tuning Photocatalytical Performance of Semiconductors

Abstract

Boosting photocatalytic performance via external fields is an alternative and effective solution for improving the application performance of existing photocatalysts. Herein, using α-Fe₂O₃-decorated TiO₂ nanotube arrays as a model, we demonstrate the influence of magnetic field (MF)-direction on the photogenerated charge-carrier transfer behavior at plasmonic metal/semiconductor interfaces. For the first time, the photocatalytic activity is also found to correlate with the plasmonic metal species while applying an external MF. As verified by first-principles calculations, the spin-orbit coupling of metal contributes to the charge-carrier transfer. To highlight the anisotropic MF-tuning effect in practical applications, the as-prepared architecture is applied for photocatalysis-triggered drug delivery. The delivery rate can be remarkably accelerated by ∼38% under a tiny MF (0.4 T) with the proper direction. The findings in this research may provide new insight into designing semiconductor architectures for boosting the photocatalytical performance in an external MF.