Sol–gel synthesis of macroporous barium zirconate monoliths from ionic precursors via a phase separation route

Monolithic macroporous barium zirconate derived from ionic precursors has been successfully prepared via a phase separation route in the presence of poly(ethylene oxide) (PEO) and propyleneoxide (PO). Poly(ethylene oxide) (PEO) acts as a phase separation inducer, while propyleneoxide (PO) acts as a gelation accelerant in the sol–gel process. Appropriate choice of poly(ethylene oxide) (PEO) and propyleneoxide (PO) allows the production of continuous macroporous monolithic gel with a porosity of ca. 63% and a macropore size of 1.8   µm. Some BaCl 2 recrystallizes in the dried gel, and subsequently tetragonal ZrO 2 phase precipitates after heat-treated at 800   °C. The crystalline phase barium zirconate forms after heat treatment at 1100   °C in air, while the macroporous structure is preserved with a slight increase of porosity and a decrease of macropore size.