Morphology control of ZnO nanostructures by catalyst-free and seed-mediated simple aqueous solution growth method

• ZnO nanostructures were prepared on glass substrate by solution growth approach.
• Co-existence of various ZnO particles lead to the formation of different morphologies.
• Strong UV emission in PL spectra indicate high optical quality of grown nanostructures.
• The shift in PL bands with growth time is attributed to the quantum confinement effect.

In the present investigation the catalyst-free and seed-mediated simple aqueous solution growth approach for the preparation of various ZnO nanostructures (nanoplates, cauliflower, hexagonal shaped hollow and solid nanorods) on amorphous glass substrate at 95 °C is reported for the first time in the literature. Wurtzite structure of grown nanostructures was confirmed by the XRD analysis. The strong UV peak (385 nm) corresponding to the band-edge-emission was observed in the photoluminescence spectra. The slight shift observed in PL bands with growth time is attributed to the quantum confinement effect owing to variation in nanostructure size and/or shape. The possible mechanism for the formation of different morphologies of ZnO nanostructures is elaborated.