Nifedipine and metronidazole photodegradation using sustainable Raphanus sativus leaf extract mediated zirconia nanoparticles: A novel green solution for pharmaceutical waste treatment

The increasing presence of pharmaceutical pollutants in wastewater necessitates the development of sustainable and environmentally friendly remediation techniques. This study will discuss an eco‐friendly and cost‐effective approach for synthesizing zirconium dioxide nanoparticles (ZrO 2 ‐NPs) using Raphanus sativus leaf extract. This inexpensive synthesis approach utilizes the bioactive compounds of the leaf extract as natural reducing and stabilizing agents, eliminating the need for hazardous chemical compounds. The synthesized ZrO 2 ‐NPs were characterized by using UV–Vis spectroscopy, Zeta sizer, Fourier‐transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), and energy‐dispersive X‐ray spectroscopy (EDX), confirming their high purity, stability, and uniform nanoscale morphology. The nanoparticles exhibited a strong absorption peak at 339 nm, which confirms ZrO 2 ‐NPs, an optical bandgap of 3.68 eV, and a mean particle size of 138 nm. Photocatalytic experiments in the presence of UV irradiation verified the efficacy of ZrO 2 ‐NPs in degrading pharmaceutical contaminants, such as Metronidazole (MNZ) and Nifedipine (NIF). The degradation efficacy of nanoparticles for NIF demonstrates optimal performance under acidic conditions (57%), whereas basic conditions are more preferable for the degradation of MNZ (78%). Kinetic analysis showed that the degradation of both antibiotics followed a pseudo‐first‐order reaction, with rate constants of 0.0189 min −1 for MNZ and 0.00906 min −1 for NIF. These findings highlight the effectiveness of green‐synthesized ZrO 2 nanoparticles as a sustainable photocatalyst for treating pharmaceutical‐contaminated wastewater. This approach supports global efforts to reduce environmental pollution in line with the principles of green chemistry.