Controllable ZnO Architectures by Ethanolamine-Assisted Hydrothermal Reaction for Enhanced Photocatalytic Activity

Controllable ZnO architectures with different morphologies were synthesized via an ethanolamine-assisted one-pot hydrothermal method. By adjusting reaction conditions such as the molar ratio between Zn(OAc)₂ and NaOH and the volume ratio of the ethanolamine/water, the flowerlike, spindlelike, swordlike, and umbellarlike ZnO architectures of the hexagonal phase have been obtained. The as-prepared ZnO products were characterized by FE-SEM, TEM, XRD, BET, PL, and Raman spectroscopy. The ethanolamine significantly influenced the morphology of ZnO products, which is related to the competitive adsorption between ethanolamine and [Zn(OH)₄]²⁻ to ZnO nuclei. Their PL spectra depend on their morphologies and phase structures. The morphology-dependent photocatalytic performances in the degradation of methylene blue under UV illumination were observed, in which the flowerlike ZnO structures exhibit highest activity for their most irregular surface Zn sites.