Facet-controlled synthesis of silver microsheets for printed flexible conductive film based on SO42-and Ce4+ions: An experimental and DFT study

It is widely accepted that polymeric surfactants adsorbed on the surface of silver sheets will affect their conductivity. Here a novel seed-mediated growth method without using polymeric surfactants is proposed to synthesize uniform microsheets in aqueous solution. The roles of SO42-and Ce4+ are discussed in detail. The possible formation mechanism of microsheets is presented. The results of density functional theory (DFT) calculation demonstrate that the binding energies of SO42-on Ag(111), Ag(110), and Ag(100) facets are -4.56, -4.34, and -4.10 eV respectively, indicating that SO42-are preferentially adsorbed on the Ag(111) facet. The analyses of charge density difference and density of states (DOS) indicate that the adsorption of SO42-on Ag surfaces is chemical adsorption, in agreement with the results of XPS and FT-IR spectrum. The flexible conductive film using as-synthesized silver microsheets as the conductive filler shows lower bulk resistivity (1.2 x10-5 omega.cm) than that using the commercial ball-milled silver microsheets as the conductive filler (8.0 x10-5 omega.cm) under the same silver content conditions (80 wt%), which demonstrates good application prospects in printed electronics.