Hierarchical V2O3 spiny hollow nanosphere for efficient adsorption of precious metal ions in complicated matrices

Treatment of precious metals in electronic waste has attracted tremendous attention and is essential for both environmental protection and resource sustainable development. In this study, a novel adsorbent for precious metal ions, V 2 O 3 spiny hollow nanospheres (p-V 2 O 3 SHN), was synthesized through a one-step hydrothermal-assisted methodology for the adsorption of Au(III), Ag(I), Pd(II), and Pt(IV) from the leaching solution of electronic waste. The results reveal that the p-V 2 O 3 SHN hierarchy was successfully constructed with a hollow structure and dense spiny morphology. The prepared p-V 2 O 3 SHN can effectively remove precious metal ions such as Au(III), Ag(I), Pd(II), and Pt(IV), with the selective capture order being Au(III) > Ag(I) > Pt(IV) > Pd(II) > other metal ions. This superior adsorption capability can be attributed to the multi-diffusible, intermingled composition, and numerous active sites decorating the p-V 2 O 3 SHN hierarchy, facilitating the uptake of Au(III), Ag(I), Pd(II), and Pt(IV) ions from electronic waste. The Langmuir model provided a better fit for the uptake process, revealing maximum uptake capacities of 833.33 mg/g for Au(III), 370.37 mg/g for Ag(I), 77.51 mg/g for Pd(II), and 42.01 mg/g for Pt(IV) on p-V 2 O 3 SHN. Remarkably, p-V 2 O 3 SHN exhibited a robust affinity for the adsorbate due to the presence of surface defects and reduction. The new p-V 2 O 3 SHN also demonstrated good reusability for three sorption cycles, highlighting its potential for electronic waste treatment. Due to its facile synthesis and excellent efficiency, hierarchical p-V 2 O 3 SHN presents itself as a promising candidate for the selective uptake of Au(III), Ag(I), Pt(IV), and Pd(II) from electronic waste.