Photo-induced enhancement of hydrogenation activity for ruthenium nanoparticles immobilized on carbon dots

Abstract

Ruthenium nanoparticles immobilized on environmentally benign luminescent carbon dots act as hydrogenation catalysts, whereby light irradiation results in greatly enhanced activity. Nitrogen-doped carbon dots were prepared by hydrothermal treatment, and served as supports for the organometallic synthesis of 2.1 nm Ru NPs. UV-irradiated Ru@CDs proved 1.5–13 times more active for CC hydrogenation of α–β unsaturated ketones under mild conditions (3.5 bar H₂, 60 °C, in water/butan-1-ol) than when used in the dark. Reference experiments and mechanistic investigations rationalize this activity enhancement by a transfer of electron density from the irradiated CDs to the Ru NPs. The strong synergistic effects arising from the combination of CDs and Ru NPs under UV are potentially more broadly accessible with other CDs structures and metal NPs compositions.