A facile green synthesis of nanostructured Gold-Silver@Carbon (Au-Ag@C) nano catalyst and its applications

In this communication, the room-temperature synthesis of gold-silver nano-structures using ascorbic acid (AA) by simple one-step process is reported. Furthermore, the core-shell-type of gold-silver@carbon catalyst (Au-Ag@C) has been derived by microwave irradiation. The surface morphology expresses the neat single metal and bimetal formation. The AA acts as a reductant as well as a stabilizer of metal nanoparticles (MNPs). The microscopic studies reveal the formation of MNPs as quantum dots (similar to 3-5 nm). The excess reductant has been used as a precursor for carbon and in some case it forms as nanowires. The catalyst Au-Ag@C shows the excellent catalytic activity toward 4-nitrophenol reduction at room temperature. The proposed method is facile, fast and eco-friendly for the synthesis of Au-Ag MNPs.