Mass fabrication of 2D nanostructure (ZnO) in chemical growth solution using tip induced lithography.

The present article reports an accelerated growth technique for fabrication of 2D assembly of ZnO nanostructure and investigated the impact of concentration variance on their grown morphology. The combination of zinc nitrate hexahydrate [Zn (NO₃)₂ · 6H₂O] and hexamethylenetetramine (HMTA) is employed as growth solution having pH value of 6.0. The assembly of 2D nanostructures grown on microtip is accelerated by introducing the ultrafine discharge in the chemical growth solution. The synthesis, deposition, and growth time were limited to 20 seconds only. After deposition and growth, annealing heat treatment was applied at 95°C for 45 minutes to eliminate any impurities or crystal defects. The structural/morphological characterization through FESEM confirms that the fabricated nanostructure is of 2D nanosheet-like at lower molar concentration (0.10 M). Nevertheless, at higher concentration (0.20 M), the grown morphology changes to marigold flower-like structure with porousness in its crystal structure. The chemical characterization through EDX confirms the dominance of the ZnO in the fabricated nanostructure. The XRD results confirm the phase pure hexagonal wurtzite structure of ZnO with an average crystalline thickness of ≈27 nm. The availability of functional group and molecular fingerprint corresponds to ZnO stretching is identified by FTIR while elemental composition and their chemical states were analyzed by XPS. [ABSTRACT FROM AUTHOR]