An electroactive single-atom copper anchored MXene nanohybrid filter for ultrafast water decontamination

Abstract

Single-atom catalysts possess attractive electrocatalytic ability for degrading contaminants owing to their desirable characteristics compared with bulk counterparts. Herein, single Cu atoms anchored on Ti₃C₂T_x MXene (Cu-SA/Ti₃C₂T_x) have been demonstrated as a highly reactive and robust nanohybrid filter for ultrafast removal of micropollutants via electro-peroxymonosulfate (PMS) activation. Sulfamethoxazole, a typical antibiotic, is observed to fully degrade via a single-pass through the nanohybrid filter (<150 ms) at 1.5 mL min⁻¹. Both experimental and theoretical studies verified that the Cu–O₃ are the active sites for electro-PMS activation to produce ¹O₂ and induce electron transfer for SMX degradation. As a result of the size effects, the HO˙ radicals dominate the SMX degradation process when anchoring Cu nanoparticles to the Ti₃C₂T_x nanosheets. This study provides a proof-in-concept demonstration of the free-standing Cu-SA/Ti₃C₂T_x nanohybrid filter that may find important applications in addressing the global problem of water pollution.