PEG-Assisted Preparation of Single-Crystalline Cu2O Hollow Nanocubes

Single-crystalline Cu 2 O hollow nanocubes were fabricated via a precursor hydrolysis process in aqueous solution at room temperature. The hollow structures were studied in detail using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and high-magnification TEM (HR-TEM) techniques. During the synthesis process, the addition of NaOH and PEG was the key factor responsible for the formation of well-defined single-crystalline hollow structures. The nanocube size could be tuned between 50 and 200 nm by simply adjusting the reagent concentration and solvent. Furthermore, the size-dependent UV−vis adsorptions were characterized.