Optimization of electrochemical regeneration of intercalated MXene for the adsorptive removal of ciprofloxacin: Prospective mechanism

Abstract

2D-Ti₃C₂T_x MXene nanosheets intercalated with sodium ions (SI-Ti₃C₂T_x) were synthesized and utilized in simultaneous adsorption and electrochemical regeneration with ciprofloxacin (CPX). The primary focus of this study is to investigate the long-term stability of SI-Ti3C2Tx MXene and to propose the underlying regeneration mechanisms. The successful synthesis of Ti₃AlC₂, Ti₃C₂T_x MXene, and SI-Ti₃C₂T_x MXene was confirmed using X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. Electrochemical regeneration parameters such as charge passed, regeneration time, current density, and electrolyte composition were optimized with values of 787.5 C g^-1, 7.5 min, 10 mA cm^-2, and 2.5w/v% sodium chloride, respectively, enabling the complete regeneration of the SI-Ti₃C₂T_x MXene. In addition, the electrochemical regeneration significantly enhanced CPX removal from the SI-Ti₃C₂T_x MXene owing to partial amorphization, disorderliness, increased functional groups, delamination, and defect creation in the structure. Thus, the synthesized nano-adsorbent has proven helpful in practical water treatment with optimized electrochemical regeneration processes.

Keywords: Adsorption; Ciprofloxacin; Divided cell; Electrochemical regeneration; MXene.