In this recent research article, zinc oxide nanoparticles (ZnO-NPs) were successfully synthesized using the conventional hydrothermal technique. The present study determined comprehensive characterization of metal oxide-based nanoparticles and adsorption efficacy for heavy metal ions. X-ray diffraction (XRD) and Fourier transform infra-red (FT-IR) spectroscopy confirm alteration in the specific functional group and hexagonal structures within the synthesized ZnO-NPs. Furthermore, N2 adsorption-desorption methodology application achieved a substantial 26.777m2/g surface area, as it accurately demonstrates with the Brunauer-Emmett-Teller (BET) analyzer. Additionally, the SEM-EDX analytical technique is employed to address the ZnO-NPs and heavy metal ions interactions, revealing a promising insight. Although, the batch adsorption kinetic experiment expresses a higher degree affinity of ZnO-NPs for cupric ions (Cu2+) compared to chromium (Cr3+), lead (Pb2+) and nickel (Ni2+). The maximum adsorption capacity (88.547 mg/g) was attained at optimal conditions (pH 4, 1 g/l adsorbent dose, 250-minute contact time and 50 mg/l initial Cu2+ ion concentration). Furthermore, the adsorption process illuminates chemisorption mechanism, which point out the monolayer type removal of heavy metal ions, as evidently confirms with pseudo-second-order kinetics model. The present study shows the potential of ZnO-NPs in eradicating positively charged heavy metal ions, particularly Cu2+ ions, from contaminated wastewater streams. This study findings advocate in a full support to the metal oxides-based nanomaterials, an outstanding role in the purification of contaminated wastewater.