LAUSR

Abstract We report the preparation of the Au@silica Janus nanosheets by materialization of the emulsion interface and further functionalization with Au nanoparticles. The amphiphilicity and emulsification property of Au@silica Janus nanosheets were not affected by the grown Au nanoparticles. The catalytic performance of the Au@silica Janus nanosheets was explored using the reduction reaction of p-nitrophenol and p-nitroanisol as model reactions in homogenous reaction and emulsion interfacial reaction, respectively. The results indicated that the Au@silica Janus nanosheets exhibited excellent catalytic activity for the reduction reaction of p-nitrophenol in the homogenous reaction. In emulsion interface, the conversion of p-nitroanisol was 16-fold higher than that of the two-phase interface, which could attribute to the expanded active areas and the favorable mass transfer at the emulsion interface. The recovery of the Au@silica Janus nanosheets was simply realized and could be reused with 100 % catalytic activity. Compared with the particle-like Janus catalyst, the Au@silica Janus nanosheets could achieve better catalytic efficiency with a more low content. The conception of emulsion interfacial catalysis with Janus catalysts provides an avenue for conventional heterogeneous reactions.