Water-driven formation of luminescent Zn2GeO4 nanorods from Zn-containing Ge nanoparticles

Single-crystalline Zn2GeO4 nanorods were formed by submerging Zn-containing Ge nanoparticles (ZCGNs) in water at room temperature. These nanorods with the diameter ranging from several tens to more than 100 nm and the length of several micrometers exhibit a blue-green luminescence peak at 450 nm. Due to the surface instability of Ge in water, the agglomerates of crystalline ZCGNs keep oxidizing, and gradually transform into amorphous membranes composed of Zn, Ge, and oxygen. Zn2GeO4 nanorods then grow out directly from the amorphous membranes after further aging. This novel transformation route may provide a new thinking for preparing similar 1-D Ge-based ternary oxides or other 1-D nanomaterials.