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

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.