Electrocatalytic oxidation of antidiabetic drug metformin adsorbed on intercalated MXene.

Two-dimensional (2D) Ti 3 C 2 T x transition metal carbide (MXene) nanosheets intercalated with sodium ions (SI–Ti 3 C 2 T x MXene) were used in the adsorption and electrochemical regeneration process for removal of the antidiabetic drug metformin (MF) as a model emerging pollutant. After MF adsorption, SI–Ti 3 C 2 T x MXene oxidized the MF on its surface through its electrocatalytic activity at very low current density and cell potential. For complete oxidation the optimum parameters were 0.525 C g−1, 0.005 mA cm−2, and pH 6 in absence of NaCl or 26.25 C g−1 and 0.5 mA cm−2 in the presence of 2.5 w/v% NaCl. The overall regeneration of SI–Ti 3 C 2 T x is governed by a combined mechanism, i.e., desorption followed by degradation. The degradation mechanism, such as direct electron transfer or indirect oxidation, depends on the applied operating conditions. Thus, the investigation suggests that these 2D sheets are good nanoadsorbents as well as good electrocatalysts and proves their usefulness in practical water-treatment applications. [Display omitted] • SI–Ti 3 C 2 T x MXene was successfully synthesized for metformin adsorption and electrocatalytic degradation. • SI–Ti 3 C 2 T x MXene showed 100% adsorptive capacity for multiple adsorption and regeneration cycles. • The physicochemical characteristics of MXene were retained after multiple cycles of adsorption and regeneration. • SI–Ti 3 C 2 T x MXene showed excellent electrocatalytic properties, which enabled oxidation at low cell potentials. • The proposed system should be useful for practical wastewater treatment applications. [ABSTRACT FROM AUTHOR]