Outward conversion of core-shell nanostructured ZnS microspheres to mesoporous ZnO onesElectronic supplementary information (ESI) available: More general and HR-TEM images, TG-DTA curves of the pristine ZnS sample in N2 and O2 flow respectively, and PL spectra of the samples excited by 325 nm. See DOI: 10.1039/c3ce27110b

In this paper, a new core-shell nanostructure is proposed which is based on ZnS microspheres but the core and shell nanostructures are different. The conversion from such core-shell ZnS nanostructures to Zn(S,O)@ZnS ones and porous ZnO microspheres has been established by annealing ZnS microspheres in air atmosphere and investigated in detail by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron diffraction. During the conversion, both physical and chemical performances such as optical and photocatalytic properties can be tuned and enhanced. An outward conversion from ZnS@ZnS core-shell nanostructured microspheres to Zn(S,O)@ZnS and porous ZnO ones.