CuZrO3@Functionalized-organic matrix as a novel composite for enhanced photocatalytic treatment of antibiotics-contaminated wastewater

Antibiotic-contaminated wastewater poses severe environmental hazards, necessitating the development of efficient and sustainable treatment strategies. In this study, a novel hybrid composite, CuZrO 3 @ethyl 2-cyano-2-((4-((4-methoxyphenyl)diazenyl)phenyl) diazenyl) acetate (ECMDA), was synthesized by coupling a perovskite oxide (CuZrO 3 ) with a nitrogen-rich organic framework (ECMDA) for the photocatalytic degradation of cefotaxime (CFX) in wastewater. The structural, optical, morphological, and surface properties of this composite were verified using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Raman spectroscopy , X-ray photoelectron spectroscopy (XPS), energetic dispersive X-ray (EDX), diffuse reflectance spectroscopy (UV–Vis DRS), Scanning electron microscopy (SEM), Transmission electron microscope (TEM) and N 2 adsorption-desorption isotherms. The collected results of these tools of analysis confirmed the successful integration between inorganic and organic components, revealing a structure of improved textural features and enhanced visible-light responsiveness. Response Surface Methodology (RSM) was employed to optimize operational parameters, achieving a maximum degradation efficiency of 98.7 ± 1.1 % under optimal conditions: 100 min, pH = 6, 1.6 g/L as catalyst dose, and 10 mg/L initial CFX concentration. Kinetic analysis revealed that the Langmuir–Hinshelwood (L–H) model provided the best fit, with an intrinsic rate constant (k L ) of 0.0218 ± 0.0013 mg/L·min and an adsorption equilibrium constant (K) of 0.0654 ± 0.0041 L/mg. The apparent rate constant (k app ) under optimal conditions was 0.015 ± 0.0009 min⁻¹, indicating a controlled surface-reaction photocatalytic degradation process. Radical scavenging experiments confirmed superoxide radicals (O₂*⁻) as the dominant reactive species driving photocatalytic activity . Recyclability tests of the presented CuZrO 3 @ECMDA showed high durability, with a slight decrease in degradation efficiency from 98.7 to 97.2 ± 2.1 % over five consecutive cycles. The composite also demonstrated excellent performance in real wastewater matrices, achieving TOC removal efficiencies of 96.3 ± 2.4 % in pharmaceutical wastewater and 94.1 ± 2.1 % in municipal wastewater. These findings establish CuZrO 3 @ECMDA as a highly efficient, stable, and reusable photocatalyst for the degradation of antibiotics and organic pollutants in wastewater, contributing to sustainable environmental remediation efforts.