Driving Reactant Molecules to Plasmonic Active Sites Using Electric Field for Enhanced Catalytic Reaction

Active points of noble metal nanocatalysts possess high catalytic activity and selectivity, but the reagent molecules are hard to confine exactly at the small active points in the practical catalytic reaction system. Here, we developed a nano-driven and confined catalysis strategy and applied it in the plasmon-enhanced catalytic reaction with Au nano-bipyramids (NBPs) as catalyst. The theoretical calculation indicates that the electric field lines converge just at the hot spots of surface-charged Au NBPs. Accordingly, in our strategy, the reactant molecules are driven into the hot spots and confined at the catalytic active sites by using an electric field around the charged Au NBPs. By using this strategy, the rate constants of the catalytic reduction reactions of 4-nitroaniline and 4-nitrobenzoic acid were 5.2 times and 5.0 times higher for Au NBPs than the references under the same reaction conditions, respectively. This work provides a potential route to improve not only the utilization of catalytic active sites but also the light conversion efficiency in plasmon-enhanced catalytic reaction.