pH-Dependent Formation of Oriented Zinc Oxide Nanostructures in the Presence of Tannic Acid

Abstract

To crucially comprehend the relaying factors behind the growth mechanism of ZnO nanostructures, the needs to understand the cause of preferences in the enhancement of desired physicochemical properties are essential. The particular oriented attachment (OA) is believed to become the cause of the classical growth pattern of ZnO nanostructures which is mainly controlled by the Ostwald ripening (OR) process. In the present work, the concerns over the systematic changes in size and the morphological surface of ZnO nanostructures upon exposure to tannic acid (TA) prepared by drop-wise method turns the particles to different surface adjustment state. Here, we assessed the TA capping ability and its tendency to influence the OA process of the ZnO nanostructures. The detailed process of the growth-based TA system via transmission electron microscopy (TEM), scanning electron microscopy (SEM), and FFT autocorrelation revealed the pH effect on their physical properties which proved the transition surface properties state of the particles from rough to smooth states due to oriented attachment. For pure ZnO nanostructures, the surface is almost smooth owing to the strong bonding particles which are then changed to coarsened surface structures upon the introduction of TA. Strong surface adsorption of Zn cations and phenol ligands mediated the agglomerated nanocrystals, surprisingly with smaller nanostructures dimension.

Tannic acid: a versatile polyphenol for design of biomedical hydrogels

“…Oxidized TA can be a reducing agent when alkaline conditions appear in the tannic solution and metal ions; 72 TA oxidizes metal ions to create metal nanostructures by forming quinones and donating electrons. 98 Although many metal NPs syntheses are based on polyphenols, TA is more favorable for gold (Au 3+ ), 99,100 silver (Ag + ), 13,101–107 zinc (Zn), 108–110 and palladium (Pd 2+ ) 111,112 nanoparticles (NPs).…”

Biodegradable Nanoprobe for NIR‐II Fluorescence Image‐Guided Surgery and Enhanced Breast Cancer Radiotherapy Efficacy

“…That is, Gd 2 O 3 nanogranules were first generated and then aggregated on the V‐Si surface to form virus‐like stacking bundles (V‐Si@Gd). [ 18 ] However, because the temperature and pH could not facilitate the subsequent Ostwald ripening required for crystallization, [ 19 ] an amorphous Gd 2 O 3 assembly was finally obtained. Interestingly, the stacking force between the nanogranules is often derived from dipole–dipole attractions, which are vulnerable to weakly acidic environments.…”

The mechanochemistry of lanthanum dihydride (LaH\(_{2}\)) with hydrogen (H\(_{2}\)) using the ball-mill process and the effect of oxidation on the resulting products

“…While oxidation might lead to changes in the chemical composition of the surface, it may not significantly alter the overall shape of the particles, especially if the deformation induced during the ball mill has already shaped them into more rounded or circular forms. However, the formation of oxides on the surface might have smoothing effects, further enhancing the appearance of rounded shapes [97,98]. Oxidation might also alter the surface energy and interactions between particles, influencing how they aggregate and adhere [99,100].…”