Modification of TiO 2 Nanoparticles with Organodiboron Molecules Inducing Stable Surface Ti 3+ Complex.

As one of the most promising semiconductor oxide materials, titanium dioxide (TiO ₂ ) absorbs UV light but not visible light. To address this limitation, the introduction of Ti ³⁺ defects represents a common strategy to render TiO ₂ visible-light responsive. Unfortunately, current hurdles in Ti ³⁺ generation technologies impeded the widespread application of Ti ³⁺ modified materials. Herein, we demonstrate a simple and mechanistically distinct approach to generating abundant surface-Ti ³⁺ sites without leaving behind oxygen vacancy and sacrificing one-off electron donors. In particular, upon adsorption of organodiboron reagents onto TiO ₂ nanoparticles, spontaneous electron injection from the diboron-bound O ^2- site to adjacent Ti ⁴⁺ site leads to an extremely stable blue surface Ti ³⁺ ‒O ^-· complex. Notably, this defect generation protocol is also applicable to other semiconductor oxides including ZnO, SnO ₂ , Nb ₂ O ₅ , and In ₂ O ₃ . Furthermore, the as-prepared photoelectronic device using this strategy affords 10 ³ -fold higher visible light response and the fabricated perovskite solar cell shows an enhanced performance.
(Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)