Synergistic catalysis of monometallic (Ag, Au, Pd) and bimetallic (Ag[sbnd]Au, Au[sbnd]Pd) versus trimetallic (Ag-Au-Pd) nanostructures effloresced via analogical techniques

Abstract

Monometallic (Ag, Au, Pd), bimetallic (AgAu, AuPd) and trimetallic (Ag-Au-Pd) nanostructures, were generated using dextran as a natural polymer. The simultaneous co-reduction of multiple metal precursors with dextran gave a fine control to produce spherical shape Ag-Au-Pd trimetallic nanostructures. Small-sized Ag monometallic nanostructures of 8.7 nm were enlarged to 15.7 nm for AgAu bimetallic nanostructures. While, trimetallic nanostructures from Ag-Au-Pd was produced with much smaller size of 3.8 nm and quite narrower size distribution of 2–7 nm. The spectral analysis confirmed that the alcoholic groups of dextran were responsible for the reduction of metal ions to produce nanostructures and consequently oxidized to aldehydic/ketonic groups. The catalytic performance of the synthesized nanostructures was evaluated for the reduction of p-nitroaniline and the results demonstrated that there was a strong correlation between catalytic activity and composition of nanostructures. Half time of the reduction was diminished from 3.93 to 0.90 min. for Pd monometallic and Ag-Au-Pd trimetallic nanostructures, respectively. Using of the trimetallic nanostructure as a catalyst results in acceleration the reduction reaction 151 times. The results showed a promising approach to boost catalytic activities of the trimetallic nanostructures which were prepared via quite simple green method at ambient conditions.