Characterization and application of alkanethiolate self-assembled monolayers on Au-coated chips for Ir(IV) and Rh(III) sorption

Abstract

Au-coated Si alpha-particle detectors have been widely used during the chemical characterization of superheavy elements that have been an area of great interest to scientists for decades. Further experiments are aimed at the functionalization of this type of detector to study the chemical properties of meitnerium. It is expected to be a member of the group 9 elements of the periodic table, and its chemical properties have not been studied before. In this study, self-assembled monolayers (SAMs) of 1-(11-mercaptoundecyl)imidazole (Im-C11-SH) and 12-mercaptododecanoic acid (MDDA) on 1 × 1 cm2 Au-coated Si and glass chips were prepared and characterized using several analytical and optical techniques: atomic force microscopy (AFM), nanoprojectile secondary ion mass spectrometry (NP-SIMS), X-ray photoelectron spectroscopy (XPS), ellipsometry, and instrumental neutron activation analysis (INAA). The coverage of Au-coated Si chips with Im-C11-SH SAMs was (99 ± 6)%. NP-SIMS showed quantitative sorption of Rh(III) from an HCl medium, the coverage of Im-C11-SH SAMs with Rh(III) was (81.3 ± 3.8)%. INAA showed quantitative sorption of Ir(IV) and illustrated that it can be adsorbed from a 5.4 μM initial Ir(IV) solution in 0.55 M HCl on the Im-C11-SH and MDDA SAMs with a surface saturation of (77 ± 12)% and (84 ± 16)%, respectively.