No abstract

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 at 25 °C and 0.1 MPa of H 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 and thus are more mobile than on an inert support, resulting in an ease in reacting with the N═O bonds in nitrobenzene absorbed on SiC to produce aniline.

The monolayer graphene–Ag nanoparticles hybrid system is fabricated as the electrooptical‐coordinated controlled substrate for surface‐enhanced Raman scattering spectroscopy. Plasmon–exciton interactions in this hybrid system are systemically investigated and applied in the field of surface catalytic reactions, manipulated by the electrooptical synergy. Experimental results demonstrate that the surface catalytic reactions can not only be controlled by plasmon–exciton coupling, but also be affected by the gate voltages and electric currents (or bias voltages). The gate voltage can tune the density of state of electrons, and electric current can make the hot electrons near the Fermi level with higher kinetic energy. Both of gate voltages and electric currents can significantly promote the efficiency and probability of plasmon–exciton‐codriven surface catalytic reactions. The electrooptical device based on plasmon–exciton coupling can be potentially applied in the fields of sensor, catalysis, energy, and environment.