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.