A novel nanomotor (ZIF-L(Co)/WSe2 nanocomposite) for nanomotor motion-based dispersive micro-solid phase extraction (NM-d-μSPE) of gold and palladium

Abstract

A novel method for the separation and enrichment of Au(III) and Pd(II) ions in mining stone and covering samples was developed, using ZIF-L(Co)/WSe₂ as a nanomotor for nanomotor motion-based dispersive micro-solid phase extraction (NM-d-μSPE). The manufactured nanocomposite was characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), and electrochemical analyses. The motion dynamics of the nanomotor have been optimized by modifying the concentration of the fuel (H₂O₂) to achieve rapid and efficient movement, which enhanced adsorption performance. Important analytical parameters, such as pH, ligand and sorbent amounts, eluent type and volume, and the influence of matrix ions, were methodically studied. The method exhibited excellent sensitivity, with detection and quantification limits of 0.93 μg L⁻¹ and 3.10 μg L⁻¹ for Au(III) and 0.83 μg L⁻¹ and 2.76 μg L⁻¹ for Pd(II), respectively. The ZIF-L(Co)/WSe₂ nanomotor showed exceptional adsorption efficiency for the simultaneous extraction of Au(III) and Pd(II) ions in the presence of H₂O₂ fuel. This method is reliable, fast, and simple, thus offering a useful method for the separation, enrichment, and quantification of Au(III) and Pd(II) in geological samples using flame atomic absorption spectroscopy (FAAS). Additionally, inductively coupled plasma-mass spectrometry (ICP-MS) was used to validate the NM-d-μSPE method.