Electrocatalytic oxidation of antidiabetic drug metformin adsorbed on intercalated MXene

Abstract

Two-dimensional (2D) Ti3C2Tx transition metal carbide (MXene) nanosheets intercalated with sodium ions (SI–Ti3C2Tx 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–Ti3C2Tx 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–Ti3C2Tx 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.