Preparation of silver nanoparticles embedded hierarchically porous AlPO4 monoliths

Abstract

Hierarchically porous AlPO₄ monoliths with well-defined macropores are prepared via a sol–gel process accompanied by phase separation. Appropriate amounts of the precursors, poly(ethylene oxide) and propylene oxide, allow the formation of a mesoporous structure with uniform macropore size distribution in the gel. A crystalline phase of tridymite forms after heat-treatment at 1000 °C in air, while the meso- and macro-porous structure is preserved, maintaining a BET surface area of 120.8 m² g⁻¹. The resultant crystalline AlPO₄ monolith is used as the host to immobilize silver nanoparticles (Ag NPs) by immersing it in silver colloid under an ambient condition. The result shows that Ag NPs were homogeneously embedded on the surface of skeletons without spoiling the appearance and macroporous structure of the initial AlPO₄ monolith. Ag NPs embedded in monolithic AlPO₄ show promise in a wide range of applications, including catalysis and separation.