Synthesis of Ag-PILC through direct insertion of silver nanoparticles into smectite interlayers

In this work, a novel process for preparing silver pillared interlayer clay (Ag-PILC) has been developed through directly inserting silver nanoparticles into smectite interlayers, which might be a good alternative for the conventional method (polycation exchange) to produce more stable PILCs with higher and more uniform basal spacing. It includes three steps: to convert smectite interlayers from negative charges into positive charges through specific adsorption of hydrolysed aluminium species; to insert negatively charged silver nanoparticles into the smectite interlayers due to electrostatic attraction, forming an intercalated compound; to calcinate the compound for obtaining Ag-PILC. X-ray diffraction, Brunauer–Emmett–Teller measurements and transmission electron microscopy were used to characterise the synthesised Ag-PILC material, showing that the new process indeed produced an Ag-PILC with high basal spacing, large specific surface area and porosity. This Ag-PILC might be applied as a catalyst in organic reactions with a high photocatalytic activity or as an adsorbent with high antimicrobial activity for water treatment.