A wide variety of new materials and their hybrids have emerged as novel adsorbents to help resolve contamination of heavy metals in water resources. In this research, copper oxide(CuO) nanoblades were synthesized in high yield using a facile chemical method. These synthesized CuO nanoblades were characterized for their topological, morphological, structural, optical, and chemical behavior using a variety of techniques including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infra red (FTIR) spectrometry, Raman spectroscopy, and UV–Visible spectroscopy. The in-depth investigation confirmed that the blade-shaped synthesized nanomaterial was in pure CuO form. The synthesized nanoblades were 3–4 nm thick and 70–200 nm in length with consistent dots of 3 nm at one side on every blade. The performance of these nanoblades was further evaluated and optimized for cadmium (Cd) removal in relation to the parameters solution pH, contact time, and adsorbent/adsorbate dose. Their cytotoxicity was also assessed for probable utilization at the industrial/commercial level. CuO nanoblades showed a maximum adsorption capacity of 192.30 mg/g for Cd (adsorbent dose: 0.5 mg/ml) and exhibited a best fit for Langmuir isotherm with R2 value of 0.99 and b =0.007. This is the first report for chemical synthesis of copper oxide nanoblades followed by their utilization for removal of cadmium ions with such high adsorption capacity.