Ultrafast synthesis of multi-branched Au/Ag bimetallic nanoparticles at room temperature for photothermal reduction of 4-nitrophenol

Abstract

We report the ultrafast synthesis of multi-branched Au/Ag bimetallic nanoparticles (BMNPs) at room temperature using tannic acid (TA) as both reducing and capping agent. Based on the UV–Vis, TEM, HR-TEM, XRD and SAED analyses, the structure and absorption properties of Au/Ag BMNPs were realized. The prepared Au/Ag BMNPs exhibited excellent catalytic activity and good cycling stability toward 4-nitrophenol (4-NP) reduction according to the synergistic effect between Au and Ag elements. In addition, the catalytic activity was further enhanced under NIR laser irradiation because of their high Surface Plasmon Resonance (SPR) efficiency. The kinetic rate constant (k) and TOF value could reach 0.13 s−1 and 1.33 s−1, respectively, under NIR light (808 nm, 1.0 W/cm2) irradiation at room temperature. We envision that the development of promising routes for high quality of BMNPs could have broad applications in catalysis and environmental governance.