Silica hollow spheres(SHSs) have attracted great attention because of their low toxicity,low density,large surface area,high chemical and thermal stability,and surface permeability.They can be widely applied in storage[1],catalysis[2],drug delivery[3,4],low-dielectric-constant materials[5],low-refractive materials[6-8],and so on.Up to now,there have been various methods to produce SHSs.Inorganic[9] or organic particles[10],such as polystyrene or calcium carbonate,were used as hard templates to create hollow cavities.However,the multistep synthetic process and the lack of structural robustness of the shells upon template removal process weaken their application.Soft templates,including oil-in-water emulsions[1],[2],vesicles[13],micelle[14,15] and gas bubbles[16],are applied widely.
