Au photosensitization can endow TiO₂ visible-light-driven photocatalytic properties. Herein, via facet-optimized brookite TiO₂ with tunable electronic band structures as the substrate, we found that intense visible light excitation of Au will result in the accumulation of hot-electrons, which will negatively shift the E_F of Au and lower the Schottky barrier, thus ensuring their consecutive injections into the CB of TiO₂; in this case, hot-electrons with more reduction potential will lead to superior photocatalytic activity.