Fabrication and Characterization of Surfaces Modified with Carboxymethylthio Ligands for Chelate-Assisted Trapping of Copper

Abstract

The metal ion chelating property was conferred onto silicon (Si) and gold (Au) surfaces by direct electrografting of the 4-[(carboxymethyl)thio]benzenediazonium cation (4-CMTBD). Infrared spectroscopic ellipsometry showed the presence of characteristic phenyl and carbonyl vibrational bands on the functionalized surfaces as a proof of existence of surface-bound organic units of 4-[(carboxymethyl)thio]benzene, (4-CMTB). The loss of diazonium group (N≡N) upon electrografting of 4-CMTBD was investigated using IR spectroscopy. A Faradaic efficiency of about 18.8-20.0% was realized in mass deposition experiments for grafting 4-CMTB on the Au surface using an electrochemical quartz crystal microbalance technique. Raman spectroscopy performed on the Si-(4-CMTB) surface after treatment with copper (Cu) ion solution provided evidence of metal ion chelation based on an observed v(Cu-O) peak at about 487 cm and a v(Cu-S) signal at about 267 cm. The binding of Cu ions by the chelating ligands also caused a red shift of about 10 cm in the Raman spectrum of the Si-(4-CMTB)-Cu surface within the spectral region, characteristic of the v(C-O) signal. X-ray photoelectron spectroscopy investigations showed indications of the Cu(II) ion species chelated by the surface-bound carboxymethylthio ligands. The functionalized surface, Si-(4-CMTB), constitutes an alternative metal ion chelating surface that may potentially be developed for applications in trace-level trapping of Cu ions.

A Three-Dimensional Porous Organic Framework for Highly Selective Capture of Mercury and Copper Ions

“…As shown in Figure 2d, a pair of double peaks at 105.1 and 101.2 eV are ascribed to Hg 4f 5/2 and Hg 4f 7/2 in the high-resolution XPS spectra, respectively. 37 Another pair of double peaks at 933.8 and 954.0 eV can be attributed to Cu 2p 3/2 and Cu 2p 1/2 , respectively, 38 accompanied by two satellite peaks at 939.1 and 943.1 eV. These indicate that adsorptions of the two metal ions occur on the surface of POFct-1.…”

A sustainable gateway to access 1,8-dioxo-octahydroxanthene scaffoldsviaa surface-engineered halloysite-based magnetically responsive catalyst

“…71,72 In addition, the emergence of two distinct peaks in the Cu 2p XPS core level spectrum positioned at 934.56 and 954.04 eV were attributed to Cu 2p 3/2 and Cu 2p 1/2 respectively, along with the shake-up satellite peaks at 943.65 and 963.70 eV, authenticating the presence of copper in its +2 oxidation state. 73,74…”

Photocatalytic Chemical CO2 Fixation by Cu-BDC Nanosheet@Macroporous–Mesoporous-TiO2 under Mild Conditions

“…For macro–meso-TiO 2 , the elements Ti, O, and C appeared in the wide-scan XPS spectrum (Figure S10a), and the Ti 2p spectrum (Figure S10b) showed that the specific peaks of Ti 2p 3/2 and Ti 2p 1/2 occurred at 464.3 and 458.6 eV, respectively, indicating the existence of Ti 4+ in macro–meso-TiO 2 . For pure Cu-BDC, the elements Cu, O, and C emerged in the wide-scan XPS spectrum (Figure S10c), and the main spectrum occurred at 954.5, 934.6, and 943.5 eV (Figure S10d), which assigned to the Cu 2p 1/2 , Cu 2p 3/2 , and typical satellite, respectively, indicating that the oxidation state of Cu in pure Cu-BDC was Cu 2+ . To investigate whether the element state changed after the combination of macro–meso-TiO 2 and Cu-BDC, we further performed XPS analysis on Cu-BDC@macro–meso-TiO 2 .…”