Modified Mesoporous Carbon Material (Pb-N-CMK-3) Obtained by a Hard-Templating Route, Dicyandiamide Impregnation and Electrochemical Lead Particles Deposition as an Electrode Material for the U(VI) Ultratrace Determination

Abstract

In this paper, a dicyandiamide-impregnated mesoporous carbon (N-CMK-3), electrochemically modified in situ with lead film (Pb-N-CMK-3), was tested as an electrode material for U(VI) ultratrace determination. The prepared carbon material was characterized by XRD, SEM-EDX, Raman, FT-IR, XPS analysis and nitrogen sorption measurements. The changes of electrochemical properties of glassy carbon electrodes (GCE) after the N-CMK-3 and Pb-N-CMK-3 modification were studied using CV and EIS methods. The modification of the GCE surface by the N-CMK-3 material and Pb film increases the electroactive area of the electrode and decreases the charge transfer residence and is likely responsible for the electrochemical improvement of the U(VI) analytical signal. Using square-wave adsorptive stripping voltammetry (SWAdSV), two linear calibration ranges extending from 0.05 to 1.0 nM and from 1.0 to 10.0 nM were observed, coupled with the detection and quantification limits of 0.014 and 0.047 nM, respectively. The Pb-N-CMK-3/GCE was successfully applied for U(VI) determination in reference materials (estuarine water SLEW-3 and trace elements in natural water SRM 1640a).

Diclofenac-Impregnated Mesoporous Carbon-Based Electrode Material for the Analysis of the Arsenic Drug Roxarsone

“…Therefore, the chromene and pyron-like oxygen groups, nitrogen groups (e.g., lactam), and aromatic carbon rings can be responsible for the basic character of the surface of the DF-CMK-3 carbon. For comparison, the physicochemical characteristics of the pristine CMK-3 carbon are included in our previous work [30].…”

“…To further improve the electrochemical properties of the GCE/DF-CMK-3/CTAB for ROX analysis, the composition of the supporting electrolyte (CH 3 COONH 4 , CH 3 COOH, and NH 4 Cl) was proposed [30]. As shown in Figure 8A, the improvement of the conductivity of the supporting electrolyte by changing the typical acetate buffer (CH 3 COONa and CH 3 COOH) to buffer solution (CH 3 COONH 4 , CH 3 COOH, and NH 4 Cl) amplifies the ROX signal to 175% of its original value.…”

“…They also have good thermal resistance and very high mechanical and chemical stability [24][25][26][27][28][29]. It is worth mentioning that CMK-3 materials have good electrical conductivity and they can therefore be successfully used in electrochemical measurements; for example, dicyandiamide-impregnated mesoporous carbonaceous material additionally electrochemically decorated with lead film (Pb-N-CMK-3) was used as a glassy carbon electrode (GCE) modifier in the case of U(VI) determination [30].…”