The Suzuki-Miyaura cross-coupling reaction is an effective process for C-C bond formation in organic synthesis. Herein, we report a NiO nanodot-decorated Pd/SiC catalyst, synthesized by atomic layer deposition, which shows high photocatalytic activity for the Suzuki-Miyaura coupling of both aryl bromides and chlorides with phenylboronic acid at 30 °C in air. The Mott-Schottky contact in SiC/Pd enhances the rapid transfer of the photogenerated electrons from SiC to Pd nanoparticles. Moreover, the energy different between the highest occupied molecular orbital of the ultrafine NiO nanodots and the Fermi level of Pd forces a spontaneous electron transfer from NiO to Pd. As a result, the concentrated electrons in the Pd nanoparticles can facilitate the cleavage of C-Br or C-Cl bonds, which normally requires rather high temperatures in thermal processes. The holes left on the SiC support can assist the cleavage of the C-B bond.