Facile One-Pot Synthesis of PbSe and NiSe₂ Hollow Spheres: Kirkendall-Effect-Induced Growth and Related Properties

A facile one-pot polyol process for the synthesis of PbSe and NiSe 2 hollow spheres, using α-Se solid spheres as starting core materials was successfully developed. The careful characterization of the time-dependent products demonstrates that the Kirkendall effect could be the involved growth mechanism for the evolution process from Se solid spheres to PbSe and NiSe 2 hollow spheres, which is schematically illustrated as a two-stage temperature-controlled, Kirkendall-effect-directed formation. The microstructure analysis shows that both the PbSe and NiSe 2 hollow spheres are polycrystalline with cubic structure. The band gap of the PbSe hollow spheres exhibits a notable size effect, and the magnetic susceptibility of the NiSe 2 hollow spheres is significantly increased compared with that of its bulk counterpart. This work indicates that the nonmetal Se solid spheres can act as an appropriate fast diffusion core material for hollow structure through Kirkendall effect in the solution phase method.