Removal of tetracycline antibiotic activity in water by stable cubic phase barium stannate-perovskite nanoparticles under energy-efficient blue light LED irradiation

Photocatalysis is promising for the degradation of antibiotic pollutants in water, which are known to cause the emergence of harmful antibiotic-resistant bacteria (ARB). Importantly, photocatalytic degradation of antibiotic pollutants in water with loss of antibacterial activity in an energy-efficient manner needs to be explored. Here, for the first time, we report degradation of tetracycline (TC), a known antibiotic pollutant in water, with removal of its antibiotic activity by cubic-barium stannate (BaSnO₃, BSO) perovskite photocatalytic nanoparticles under a blue LED light (367 nm) irradiation, (BSO/LED) system. XRD results revealed a single cubic phase of BSO with a crystallite size of 35 nm. FESEM and TEM images showed that BSO had cubic block-like morphology. BET analysis revealed the mesopores nature of BSO with a surface area of 1.1 m² g^-1. XPS confirmed the existence of Ba⁺² and Sn⁺⁴ ions. The bandgap energy of BSO was determined to be ∼3.2 eV. Importantly, photolysis of BSO under blue LED light caused complete degradation of TC in water, with a pseudo-first-order rate constant (<i>k</i> _obs) value determined as 0.0824 min^-1. Radical scavenging and ESR results revealed O₂ ^˙- and holes were profoundly generated in the BSO/LED system, causing degradation of TC along with antibiotic activity removal. Electrical energy per order (<i>E</i> _EO) was determined as 13.63 kWh per m³ per order, revealing that the BSO/LED system is energy-efficient. Further, BSO was reused four times, highlighting its stability. Degradation byproducts were predicted to be non-toxic by ecological structure activity relationship analysis. Thus, the study discloses an effective photocatalytic degradation of TC along with removal of its antibacterial activity that is needed to prevent hazardous ARB, by a stable non-lead-perovskite nano-photocatalyst under an energy-efficient LED source.