Fast and Slow Time-Scale Effects of Photoinduced Surface Oxygen Vacancies on the Charge Carrier Dynamics of TiO₂

The migration of charge carriers (e.g., electrons and holes) in metal oxides, such as TiO 2, plays a vital role in (photo)catalytic applications. Nevertheless, photoinduced surface oxygen vacancies (PI-SOVs), prompted by high-energy ultraviolet irradiation, can significantly alter the dynamics of the charge carriers. Here, we performed time-resolved atomic force microscopy measurements to quantitatively deliver effects of such surface defects on the dynamics of fast (i.e., electrons) and slow (i.e., holes) charge carriers of the TiO 2 and TiO 2 /gold nanoparticle interface. Our results show that time constants and/or energy barriers associated with the migration of charge carriers change across the sample landscape due to PI-SOVs.