Facile Synthesis of Cu₂GeS₃ and Cu₂MGeS₄ (M = Zn, Mn, Fe, Co, and Ni) Hollow Nanoparticles, Based on the Nanoscale Kirkendall Effect

Hollow nanostructures have shown charming properties beyond their solid counterparts, but the synthesis of multinary chalcogenide semiconductors with hollow nanostructures remains challenging, because of their complex components. In this work, we demonstrate a facile one-pot method to synthesize Cu 2 GeS 3 hollow nanoparticles (NPs) based on Kirkendall effect by using dissolved GeO 2 as the Ge source. A theory model according to the diffusion kinetic and reaction kinetic is established to investigate the growth mechanism of Cu 2 GeS 3 hollow NPs. By using Cu 2 GeS 3 hollow NPs as the template, quaternary Cu 2 MGeS 4 (M = Zn, Ni, Co, Fe and Mn) hollow NPs are further produced, which are more difficult to prepare, because of their excessive ion species. Furthermore, Cu 2 GeS 3 hollow NP-based gas sensors are prepared, which exhibit outstanding sensitivity for the detection of ethanol gas, because of their large surface-to-volume ratio and small grain size.