Hybrid Zirconium-Lanthanum metal-organic frameworks for solar-driven sulfamethoxazole degradation
Almudena Gómez‐Avilés, Jorge Bedia, Carolina Belver
Abstract
Novel mixed Zr-La MOFs with varying Zr:La ratios (3 ̶ 20 wt% La) based on UiO-66-NH 2 (Zr) were synthesized by a solvothermal approach and assessed for the solar degradation of sulfamethoxazole, a widely detected antibiotic in urban wastewater. The influence of La doping on the structural and photocatalytic properties was thoroughly investigated. All synthesized materials depicted the crystallographic structure of the UiO-66-NH 2 , with the incorporation of La 3+ leading to partial substitution of Zr 4+ in the [Zr–O] clusters, which resulted in a slight lattice contraction and restricted crystal growth. Photocatalytic tests revealed that the MOFs with lower La content exhibited significantly enhanced activity compared to the parent UiO-66-NH 2 , with sulfamethoxazole photodegradation rate constants (k app ) up to two times higher. Mechanistic studies using scavengers and electron spin resonance spectroscopy identified •O 2 – and holes as the predominant reactive species responsible for sulfamethoxazole photodegradation. This study demonstrates that low-level La doping is an effective strategy to boost the photocatalytic efficiency of UiO-66-NH 2 for emerging pollutant removal under solar light. • Lanthanum doping boosts photocatalytic performance of UiO-66-NH₂. • UiO-66-NH₂ maintains its structural integrity with partial La substitution. • Superoxide radicals and holes are the key reactive species in SMX degradation. • La-doped UiO-66-NH₂ shows excellent stability and reusability.