Self-assembled materials from MXene and polyoxometalates based on polymerization of dopamine in one step for non-radical dominated degradation of sulfamethoxazole

The difficulty in introducing polyoxometalates (POMs) into few-layer MXene (Ti 3 C 2 ) is caused by POMs dissolution and the easy oxidation of MXene . In this paper, a ternary composite of MXene-SiW 9 Co 3 @PDA, was synthesized in a one-step process by the self-polymerization of dopamine (DA) on few-layer MXene. The material was characterized by a large MXene interlayer spacing, low dissolution of POMs, and high oxidation resistance with good adsorption properties, excellent stability, and catalytic activity. MXene-40 %SiW 9 Co 3 @PDA degraded 98 % of sulfamethoxazole (SMX) in 30 min with a pseudo-first-order rate constant k of 0.1401 min −1 . The redox of Ti 2+ /Ti 3+ or Ti 4+ in MXene and Co 2+ /Co 3+ in POMs activated peroxymonosulfate (PMS), which generated large amounts of reactive oxygen species (ROS). As a consequence, the degradation of SMX was not dominated by SO 4 − ·, but by non-radical 1 O 2 . Additionally, this system was also efficient in degrading norfloxacin (30 min, 94 %), amoxicillin (5 min, 99 %), and tetracycline hydrochloride (10 min, 95 %). This study provides a new idea in developing two-dimensional MXene-based POMs composites and is promising in the practical application of advanced oxidation technology in wastewater treatment . • MXene-based polyoxometalate composites was synthesized by one-step procedure. • Polyoxometalates are able to enter the interlayer of MXene. • The sandwich structure reduces the leaching of polyoxometalates . • 1 O 2 produced by MXene-40 %SiW 9 Co 3 @PDA/PMS dominated the degradation of SMX. • It is potential to treat waste water with higher concentration of antibiotics.