Novel CoTeO3@β-C3N4 nanohybrids for removing pharmaceutical contaminants from natural water samples

Abstract

The whole environment is at risk due to the modern lifestyle in which antibiotic manufacturing and consumption are cornerstones. Vast amounts of pharmaceuticals from industrial effluents and urban wastewater make their way into natural water without sufficient treatment. Here, β-carbon nitride (β-C₃N₄) was made via thermal treatment of guanidine hydrochloride in an oxygen-poor environment. CoTeO₃ at 10 % and 20 % doping ratios were incorporated on the β-C₃N_4, making 10 %CoTeO₃@β-C₃N₄ (10-CoTe/β) and 20 %CoTeO₃@β-C₃N₄ (20-CoTe/β). Ciprofloxacin (CPF) was utilized for examining the β-C₃N₄, 10-CoTe/β, and 20-CoTe/β sorption capabilities. A weakly acidic medium (pH= 6) was suitable for β-C₃N₄, 10-CoTe/β, and 20-CoTe/β, which showed q_t values of 28.95, 63.59, and 93.22 mg g^-1, respectively. The pseudo-second-order was the best-fitted rate-order model for CPF sorption onto 10-CoTe/β and 20-CoTe/β. The intraparticle diffusion mechanism derived the CPF sorption on 10-CoTe/β and 20-CoTe/β. For 10-CoTe/β. The CPF sorption onto 10-CoTe/β followed the Langmuir model, was exothermic, and spontaneous in cold effluents; however, 20-CoTe/β showed the utterly opposite outcome. The 20-CoTe/β was employed to treat groundwater (G-W) and seawater (S-W) spiked with CPF (5 mg l^-1), where it showed 98.13 % and 99.73 %, respectively. The reusability of 20-CoTe/β was assessed over four successive cycles at 30 min equilibrium time, and the efficiency at the fourth cycle dropped only by 6.0 % compared to the virgin 20-CoTe/β, indicating remarkable and fast performance.