Formation of noble metal nanoparticles through chemical reduction induced by coordination-alteration of complex ions in ionic liquids and electroanalytical application
Abstract Au, Pd, and AuPd nanoparticles (NPs) were formed in ionic liquid (IL) by coordination alteration-induced redox reaction. The different affinity between transition metal ions and anionic ligands leads to the huge redox potential change when IL anion-coordinated Fe(II) or Cu(I) ions were mixed with Cl − -coordinated Au(I) or Pd(II) ions in appropriate IL, which results in a spontaneous redox reaction accompanied with the formation of NPs without additional stabilizing reagents. By manipulating the molar ratios of Fe(II) or Cu(I) to Au(I) or Pd(II), the particle size could be changed. A new technique was developed to prepare NPs-IL-carbon paste electrodes (NPs-IL-CPEs) without the use of mortar and pestle. The electrodes were used in electrochemical analysis to prove the feasibility of the entire procedure.