Efficient　catalytic　hydrogenation　of　nitroarenes　to　anilines　with　molecular　hydrogen　at　room　temperature　is　still　a　challenge.　In　this　study,　this　transformation　was　achieved　by　using　a　photocatalyst　of　SiC-supported　segregated　Pd　and　Au　nanoparticles.　Under　visible-light　irradiation,　the　nitrobenzene　hydrogenation　reached　a　turnover　frequency　as　high　as　1715　h(-1)　at　25　degrees　C　and　0.1　MPa　of　H-2　pressure.　This　exceptional　catalytic　activity　is　attributed　to　a　synergistic　effect　of　Pd　and　Au　nanoparticles　on　the　semiconducting　SiC,　which　is　different　from　the　known　electronic　or　ensemble　effects　in　Pd-Au　catalysts.　This　kind　of　synergism　originates　from　the　plasmonic　electron　injection　of　Au　and　the　Mott-Schottky　contact　at　the　interface　between　Pd　and　SiC.　This　three-component　system　changes　the　electronic　structures　of　the　SiC　surface　and　produces　more　active　sites　to　accommodate　the　active　hydrogen　that　spills　over　from　the　surface　of　Pd.　These　active　hydrogen　species　have　weaker　interactions　with　the　SiC　surface　on　an　inert　support,　resulting　in　an　ease　in　reacting　with　the　N=O　bonds　in　nitrobenzene　absorbed　on　SiC　to　produce　aniline.