Controlled Synthesis of Noble Metal@Mesoporous Carbon Colloids as Highly Active Nanocatalysts

The key concept to simplify the synthesis steps of core-shell nanocomposites is to synthesize the core and shell components together without tedious separation and purification steps. In addition, the sintering problems of carbon spheres during the high-temperature carbonization process need to be addressed with the aim of obtaining monodisperse carbon nanospheres. Through extension of our reported silica-assisted strategy, a facile one-pot strategy is reported here to synthesize noble metal@mesoporous carbon (NM@MC) core-shell colloids in which the formation and encapsulation processes of noble metal nanoparticles happen simultaneously through a series of synergetic reactions. The resulting NM@MC colloidal nanospheres show uniform and highly dispersed morphology, tunable size, high surface area, and clear core-shell structure with abundant mesopores. In particular, the Au@MC colloid shows significantly high catalytic activity in the reduction of 4-nitrophenol to 4-aminopheol thanks to the excellent catalytic performance of the Au inner core and fast mass transfer of the mesoporous carbon shell.