Hydrothermal synthesis of do-TAB/CNP@NiO nanocatalyst for efficient photocatalytic degradation of acetaminophen: Characterization, photocatalytic mechanism and degradation pathways of drug wastewater

This study reports a comprehensive evaluation of acetaminophen (ACT) photocatalytic degradation in aqueous media using hydrothermally synthesized Do-TAB/Clinoptilolite (Do-TAB/CNP), NiO nanoparticles, and a hybrid Do-TAB/CNP@NiO nanocatalyst. The prepared materials were systematically characterized by XRD, FT-IR, SEM-EDX, TEM, XRF, BET surface area, and BJH pore size analyses, confirming their crystalline structure, surface morphology, elemental composition, and porous features. The photocatalytic activity was investigated as a function of catalyst dosage, initial ACT concentration, solution pH, irradiation source, water matrix, and radical scavengers to clarify the degradation behavior and reactive species involved. Under optimal conditions, Do-TAB/CNP@NiO achieved 98.50% ± 0.75% ACT degradation within 120 min, whereas the maximum efficiency reached 99.92% ± 0.82% at 10 mg L−1 ACT under the same catalyst dosage. Kinetic analysis revealed pseudo–first–order behavior, with apparent rate constants (kapp) of 0.0061–0.0565 min−1 for catalyst dosage, 0.0117–0.0599 min−1 for ACT concentration, and 0.0218–0.0350 min−1 for water matrices. Radical scavenging tests verified the dominant contribution of reactive oxygen species and the synergistic interaction between NiO and Do-TAB-modified CNP. The hybrid catalyst exhibited stable reusability, with degradation efficiency decreasing from 98.50% to 89.68% after six cycles. Under optimized conditions, pharmaceutical degradation followed the order MET (99.90%) ' ACT (98.50%) ' SMX (88.45%) ' NAP (86.90%) ' CIP (83.89%) ' NAL (79.17%). Compared with NiO nanoparticles (70.34%), Do-TAB/CNP (63.65%), and raw CNP (54.46%), Do-TAB/CNP@NiO demonstrated markedly enhanced photocatalytic performance, indicating its strong potential for pharmaceutical wastewater treatment applications in water.