The synthesis of reliable, cost-effective, and eco-friendly ZnO piezoelectric nanoparticles (NPs) can contribute to nanotechnology applications in electronics, sensors, and energy harvesting. Herein, ZnO NPs were synthesized using a hydrothermal method under varied reaction times and adding ammonium hydroxide, which provided an advantage of a low-cost, scalable, low-temperature, and environmentally friendly process. Characterization through UV–Vis spectroscopy revealed absorption peaks between 374 and 397 nm, showing a blue shift compared to bulk ZnO (400 nm) attributable to nanoscale dimensions. Transmission Electron Microscopy (TEM) analysis indicated particle dimensions with length and width ranges from 150 to 341 nm and from 83 to 120 nm, respectively. X-ray diffraction (XRD) confirmed high-crystalline quality, with crystallite sizes calculated using the Scherrer equation. In addition, the effective mass model provided an estimated band gap that matched with the reported data. Also, the lattice parameters, interplanar distances, and Zn-O bond lengths were consistent with Joint Committee on Powder Diffraction Standards (JCPDS). Finally, a ZnO NP film was deposited on a steel substrate, which generated a displacement of 150 nm under a square wave voltage of 10 V. The piezoelectric behavior of the synthesized ZnO NPs can be useful for fabrication of piezoelectric nanogenerators. The proposed synthesis can allow ZnO NPs with potential application in electronic devices, energy harvesters, and transducers.

In this study, the effect of pure and modified hexagonal boron nitride (h-BN) nanosheet incorporation on the stability, viscosity, and electrochemical behavior of a waterborne emulsion acrylic coating was studied. The functionalization of h-BN nanoplatelets with polyacrylic acid (PAA) plasma polymerization was performed, and the successful surface modification was determined through water dispersion testing, Fourier transform infrared spectroscopy and thermogravimetric analysis, X-ray photoelectron spectroscopy, and also by transmission electronic microscopy. Later, the stability and viscosity properties of emulsion nanostructured acrylic coatings, which were previously prepared by an ultrasound-assisted mixing system, were analyzed using zeta potential and rheometry testing, respectively. The electrochemical behavior was analyzed by electrochemical impedance spectroscopy. The results prove an effective deposition of PAA films on the h-BN surfaces, which enhanced the stability and viscosity acrylic of nanostructured coatings due to the interactions between the h-BN nanoplatelets surface and emulsion acrylic paint and also with the thickener additives. On the other hand, the electrochemical analysis demonstrated a significant increase (two orders of magnitude) in corrosion resistance in the acrylic nanostructured coatings with 1 wt.% of unmodified and modified h-BN nanoplatelets concerning pure acrylic paint due to a barrier protection mechanism of corrosion inhibition. Therefore, the results demonstrate that the surface modification of h-BN by plasma polymerization (green technology) helped to solve the low dispersibility issue of BN nanosheet surfaces in a waterborne polymer matrix to obtained green nanostructured acrylic coatings with the right balance in in-can properties and corrosion inhibition of AISI 304 stainless steel.