Construction of ultra-small Pt nanoparticles @Ti3C2Tx MXene electrocatalyst for efficient and stable electrochemical hydrodechlorination of chloramphenicol

Halogenated antibiotics, especially chloramphenicol (CAP), are abused in human and poultry treatment of bacterial infections, resulting in a rising environmental risk posed by antibiotic-resistant bacteria and genes. Therefore, the degradation of CAP before release by gentle and efficient electrochemical hydrodechlorination (EHDC) has attracted tremendous interest. Platinum group metals are irreplaceable in EHDC but suffer from high cost and scarcity, necessitating strategies of reducing the particle size to increase the atom utilization efficiency. Here, ultra-small platinum nanoparticles @ Ti3C2Tx MXene (Pt@MXene) electrocatalyst was constructed through a general and facile approach. Benefitting from the synergy of electron transfer and atomic H*, 1% Pt@MXene could almost completely reduce CAP within 90 min (98.7%), and retained impressive removal efficiency (86.5%) after 25 recycling tests. Remarkably, the rate constant (k) contributed by unit mass of metal (k/ratio) of 1% Pt@MXene is 75 times higher than that of Commercial Pt/C. Two plausible degradation pathways on 1% Pt@MXene are deduced from the analysis of intermediate products. Besides, 1% Pt@MXene can be extended to actually remove the high content of CAP in the urine of hospital patients. This work paves an avenue for rational design of noble metal electrocatalysts on MXene and their applications in hydrodechlorination.