Hollow Particles of Other Metal Oxides

Deng et al. reported a facile method to prepare ZnO hollow spheres using a PS template [88]. Sulfonated PS particles dispersed in ethanol were easily coated with ZnO crystals by stirring with zinc acetate at 60 °C followed by addition of NaOH. The template was spontaneously dissolved during the reaction to yield ZnO hollow spheres, which showed good photocatalytic activity. 

Hollow inorganic particles have various potential applications such as in coatings catalysis, adsorption, and drug dehvery system (DDS) due to their imique structural features [90]. The porous shell provides diffusion pathways to their interior voids, which is particularly important for catalysis and drug dehvery. Fiuther-more, the yolk-shell structured particles containing functional cores inside the hollow interior are useful as nanoreactors for various catalytic reactions and multifunctional carriers for drug dehvery [91]. 

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