Enhanced peroxymonosulfate activation by ZIF-67/Bi/Ti@NF bimetallic system for efficient antibiotic degradation

Rising demand of tetracycline (TC) has triggered the contamination of aquatic systems, posing severe health risks. Consequently, there is a necessity to discover techniques to eradicate TC. Recently, advanced oxidation processes (AOPs) utilizing radical pathways have potentially executed the antibiotic removal. Therefore, there is an immediate need to develop materials that can simultaneously detect and effectively eliminate TC. Recent applications of AOPs utilizing SO₄^•−have effectively targeted the removal of antibiotics. This study involved the fabrication of an effective catalyst composed of ZIF-67 and bimetals (bismuth and titanium) by a hydrothermal technique on nickel foam (ZIF-67/Bi/Ti@NF). The determinants affecting ZIF-67/Bi/Ti@NF activated peroxymonosulfate (PMS) were examined. The structure of catalyst was characterized using SEM, TEM, XRD, XPS etc providing critical insights into its morphology, crystallinity. Improved TC degradation was recorded with ZIF-67/Bi/Ti@NF activated PMS without any external energy source. Under optimal conditions (ZIF-67:Bi:Ti ratio of 3:2:1, PMS dosage of 0.02 g/L, pH = 6.71), ZIF-67/Bi/Ti@NF achieved a TC removal rate of 99.4 % from an initial concentration of 10 mg/L within 10 min with a rate constant (k) of 0.187 min⁻¹. The degradation proceeded via a multi-radical pathway involving SO₄^•-, ^•OH, and O₂^•- as dominant reactive species. Until 4th cycle of usage, the catalyst showed satisfactory degradation. This system not only degraded TC, but also showed efficient removal of other emerging pollutants like carbamazepine, I buprofen, naproxen highlighting its broad-spectrum applicability and potential as an innovative catalyst for aquatic environmental remediation.