Combustion synthesis of high-entropy carbide nanoparticles for tetracycline degradation via persulfate activation

The development of high-entropy carbide nanoparticles merits untold scientific and technological potential, yet their synthesis remains a challenge using conventional synthetic techniques. Herein we present a facile, rapid and low-cost route for the combustion synthesis of (Ta 0.25 Nb 0.25 −Zr 0.25 Ti 0.25 )C high-entropy carbide (HEC-1) nanoparticles by self-propagating reaction of metal oxides, carbon and Mg mixture precursors in NaF salt media for the first time. The combustion synthesis possibility of HEC-1 is first analyzed theoretically from thermodynamic aspects, and then the ultrafine HEC-1 nanoparticles (average particle size: ∼19 nm) are synthesized successfully by the combustion synthesis technique at combustion temperature of ∼1487 K, duration of 63 s, and heating rate of ∼68 K s −1 . The as-synthesized HEC-1 nanoparticles possess high compositional uniformity and low oxygen impurity content of 2.98 wt%. To prove their utility, the as-synthesized HEC-1 nanoparticles are utilized as an effective persulfate activation catalyst for the degradation of tetracycline pollutant in groundwater or wastewater and a removal efficiency of ∼65.5% for tetracycline is obtained after 10 h.