Preparation and Characterization of Flower‐Like Bi ₂ WO ₆ ‐Based Composites for Enhanced Visible Light Photodegradation of Amoxicillin: A Study of Pathway Degradation

ABSTRACT This research examined the characteristics and performance of a Bi 2 WO 6 (BWO) based composite manufactured in a simple way for the degradation of amoxicillin (AMX) under 50‐watt LED‐COB visible light. Various techniques such as SEM/EDS, TEM, XRD, FTIR, BET, TGA, XPS and EPR were used to characterize the BWO composite. The impact of photocatalyst dosage, initial pH and AMX concentration on the catalytic decomposition of AMX was studied. Based on the EPR signals, • OH and • O 2 − are effective factors in the degradation of AMX. The findings indicated that the effectiveness of AMX degradation was influenced by pH, with optimal performance achieved at pH 3, a concentration of 20 mg/L AMX, a catalyst dose of 0.2 g/L and a temperature of 25°C, resulting in a 92.5% removal rate. The investigation also showed that the photocatalytic breakdown of AMX followed the Langmuir–Hinshelwood equation. Additionally, the photodegradation efficiency of AMX increased with temperature, reaching over 98% at 40°C and 50°C. At pH 3, the BWO composite's reusability for the degradation of AMX decreases with five reaction cycles from 98.00% in the first cycle to 78.00% in the fifth, without washing or thermal treatment. Using LC–MS/MS analysis, the breakdown mechanism and potential degradation products of AMX were investigated. This study presents a single‐step hydrothermal approach for fabricating Bi 2 WO 6 /Bi 2 O 3 heterojunctions, marking a significant advancement in the development of sustainable and eco‐friendly photocatalytic materials for the removal of antibiotics and organic contaminants from water.