Synthesis of Amphiphilic Ionic Liquids Terminated Gold Nanorods and Their Superior Catalytic Activity for the Reduction of Nitro Compounds

Uniform gold nanorods were prepared via a three-step seed-mediated growth method using a long-chain ionic liquid (IL), 1-dodecyl-3-methylimidazolium bromide (C(12)mimBr), as a capping agent. Both AgNO3 and HNO3 were used in the synthesis process. The aspect ratio, R, of the nanorods was increased when AgNO3 was replaced by HNO3. HRTEM revealed that these well-crystallized nanorods are all enclosed by five {100} facets and their cross section is pentagon. The interaction energies between the individual surfactants and different gold crystalline planes were calculated using a molecular dynamics simulation. The results showed that the interaction energies between the C(12)mimBr and different gold crystalline planes were smaller than those of CTAB based system. The catalytic experiments showed that the short gold nanorods had excellent catalytic efficiency for the reduction of nitro compounds.