Modification of TiO2 Nanoparticles with Organodiboron Molecules Inducing Stable Surface Ti3+ Complex

Summary As one of the most promising semiconductor oxide materials, titanium dioxide (TiO2) absorbs ultraviolet (UV) light but not visible light. To address this limitation, the introduction of Ti3+ defects represents a common strategy to render TiO2 visible-light-responsive. Unfortunately, current hurdles in Ti3+ generation technologies impeded the widespread application of Ti3+ modified materials. Herein, we demonstrate a simple and mechanistically distinct approach to generating abundant surface-Ti3+ sites without leaving behind oxygen vacancy and sacrificing one-off electron donors. In particular, upon adsorption of organodiboron reagents onto TiO2 nanoparticles, spontaneous electron injection from the dibron-bound O2- site to adjacent Ti4+ site leads to an extremely stable blue surface Ti3+‒O-• complex. Notably, this defect generation protocol is also applicable to other semiconductor oxides including ZnO, SnO2, Nb2O5 and In2O3. Furthermore, the as-prepared photoelectronic device using this strategy affords 103 fold higher visible light response, and the fabricated perovskite solar cell shows an enhanced performance.