A Series of Cobalt-Based Coordination Polymer Crystalline Materials as Highly Sensitive Electrochemical Sensors for Detecting Trace Cr(VI), Fe(III) Ions, and Ascorbic Acid

Abstract

Convenient, sensitive, and reliable detection of multiple heavy-metal ions is a significant and challenging task with the use of high-yielding and easily synthesized materials. To solve this challenge, five cobalt-based coordination polymers (CPs), [Co2(4-dptb)2(1,3-BDC)2]·2H2O (1), [Co­(4-dptb)­(5-DIP)] (2), [Co­(4-dptb)­(5-NIP)] (3), [Co­(4-dptb)­(5-AIP)] (4), and [Co­(4-dptb)­(5-MIP)] (5) (4-dptb = N 3,N 4-bis­(pyridin-4-ylmethyl)­thiophene-3,4-dicarboxamide, 1,3-BDC = 1,3-benzenedicarboxylate, 5-DIP = 5-hydroxyisophthalic acid, 5-NIP = 5-nitroisophthalic acid, 5-AIP = 5-methylisophthalic acid, 5-MIP = 5-aminoisophthalic acid), have been synthesized by hydrothermal methods. A remarkable electrochemical sensing for Cr­(VI) and Fe­(III) was confirmed by cyclic voltammetry (CV) and current–time curves (i–t). The results showed that all CPs have a low limit of detection (LOD) of Cr­(VI) and Fe­(III) and fast electrochemical responses of within 3 s. At the same time, compounds 1–5 have a significant electrocatalytic oxidation effect on ascorbic acid (AA) and can be used as electrochemical sensors for AA.

Electrochemical activation of CO2by MOF-(Fe, Ni, Mn) derivatives of 5-aminoisophthalic acid and the thiazole group influence on its catalytic activity

“…The data are similar to those reported in the literature. 18 The distances S(1)–C(10) (1.715 (3) Å) and S(1)–C(11) (1.719 (2) Å) are of the same length, with an angle of C(10)–S(1)–C(11) of 89.58 (12)°. The bond N(2)–C(11) (1.300 (3) Å) is consistent with a double bond NC.…”

Cobalt complexes tuned by Anderson-type polyoxometalates and bis-amide derivative ligands featuring a ‘V’-like connector for efficient ampere sensing and the visible-light catalytic reduction of Cr(vi)

“…4), so the redox processes were surface-controlled. 43 Considering the excellent redox ability of 1–4 -CPEs, the electrocatalytic reduction behavior of Cr( vi ) was further studied. As shown in Fig.…”

Anderson-type polyoxometalate-based sandwich complexes bearing a new “V”-like bis-imidazole-bis-amide ligand as electrochemical sensors and catalysts for sulfide oxidation

“…To S3-S6 in the ESM) [14,34,[38][39][40][41][42][43][44][45][46][47][48][49][50]. By comparing the LODs of 1-3-CPEs for the above ions, the detection ability was found to follow the order 1-CPE > 2-CPE > 3-CPE.…”