In this work, a simple and efficient strategy for fabrication of silica hollow spheres (SHSs) has been successfully introduced with a one-step microwave-assisted aerosol process using silica nanoparticles (SiO2, 12-50 nm) and NH4HCO3 as precursor materials. This approach combines the merits of microwave radiation and the aerosol technique. And the formation of SHSs is ascribed to solvent evaporation and the as-generated gas from NH4HCO3 decomposition in the microwave reactor. The morphology of the SHSs can be easily tuned by varying the residence time, amount of NH4HCO3 and silica sources. The formation mechanism of SHSs was also investigated by structure analysis. In addition, the hollow spheres exhibited remarkable sustained release of potassium persulfate, by loading it into the porous structures. The results provide new sights into the fabrication of inorganic hollow spheres via a one-step process. (C) 2015 Elsevier Ltd. All rights reserved.