Synthesis of porous silica structures with hollow interiors by templating nanosized calcium carbonate

Shape-controlled porous silica structures with hollow interiors were synthesized by using CaCO3 nanoparticles with the corresponding morphologies and sizes as the inorganic templates. Through the hydrolysis of sodium silicate, a continuous coating of SiO2 was deposited over the surface of CaCO3 cores to form core–shell structures. Hollow silica structures were finally obtained after calcining process and dissolving CaCO3 in HCl dilute solution. The as-prepared hollow products were characterized with TEM, SEM, EDS, BET, and FT-IR.