Design of porous Ag platelet structures with tunable porosity and high catalytic activity

Abstract

Porous Ag structures have recently attracted great interest due to their unique characteristics, relatively low cost and good biocompatibility. Shape-, size-, porosity-, and crystallinity-controlled and surface defect tailored synthesis of porous metal materials is of scientific significance yet greatly underdeveloped because of the lack of rational design strategies. Here, a low cost and facile synthetic route is presented to produce regular porous Ag platelet structures with controlled size, porosity, crystallinity and surface defects by a two-step process. Initially, size-tailored regular Ag platelet precursors from 2.5 μm to 36 μm are obtained by merely adjusting the solution pH value; meanwhile D-glucose is introduced as a structure-directing agent. Subsequently, thermal treatment is performed to afford the porous Ag platelet structures. Simply by optimizing the annealing time, temperature and heating rate, porous Ag platelets with effectively tunable porosity, crystallinity and surface defects can be achieved. The porous Ag platelet structures could catalyze the reduction of p-nitrophenol and dyes quite effectively at room temperature, which is attributed to their regular morphologies, porosity, high surface-to-volume ratio, short diffusion length and good permeability. Moreover, these porous Ag platelet structures because of their unique morphology and network characteristics will exhibit excellent electrochemical catalytic activity, or act as outstanding electrodes, sensors, actuators, etc.