A simple approach to synthesize KNiF3 hollow spheres by solvothermal method

Potassium nickel fluoride (KNiF3) hollow spheres with diameters of 200-400 nm have been solvothermally synthesized at 110 °C using KF and NiCl2 as reactants in ethanol, without additional template materials or surfactants. The results of XRD and XPS indicate that the products are perovskite-type KNiF3. TEM microphotos show that the hollow spheres are composed of KNiF3 nanoparticles with an average size of 10 nm, and the wall thickness is 20-40 nm. UV-vis and PL spectra have recorded the optical properties of KNiF3 hollow spheres. A possible mechanism for the formation of KNiF3 hollow spheres is also discussed.