Photocatalytic <scp>UV</scp> / <scp> H ₂ O ₂ </scp> /magnetite induced degradation of bromocresol purple dye in aqueous solution: Effect of <scp> H ₂ O ₂ </scp> and kinetic studies

Abstract The degradation of organic dyes in wastewater is a major environmental concern worldwide because of their toxicity and carcinogenic effects. In recent years, photocatalytic processes emerged as a favorable technology for the treatment of organic pollutants. Herein, we investigated the effectiveness of ultraviolet (UV)/hydrogen peroxide (H 2 O 2 )/magnetite (Fe 3 O 4 )—induced degradation process to degrade bromocresol purple dye in water. Fe 3 O 4 nanoparticles were prepared via co‐precipitation and characterized using various analytical techniques. Fe 3 O 4 nanoparticles exhibited UV absorption at 438 nm with direct and indirect band gaps of 1.89 and 0.45 eV, respectively. Energy‐dispersive x‐ray spectroscopy confirms iron (~0.7, 6.5, 7 keV) and oxygen (~0.5 keV). Thermal gravimetric analysis indicates thermal stability of up to 850°C with ~2.31% weight loss. The impact of operating parameters such as pH, reaction time, photocatalyst, and H 2 O 2 quantity on photodegradation efficiency was investigated. The highest percentage degradation efficiency of each parameter on dye degradation was determined as follows: pH (73.03%), reaction time (39.63%), catalyst amount (32.77%), and H 2 O 2 volume (37.33%). Kinetic studies showed the photocatalytic degradation of bromocresol purple dye by Fe 3 O 4 nanoparticles followed pseudo‐first‐order kinetics with a rate constant (k) of 1.4 × 10 −3 min −1 . The proposed photocatalytic mechanism involving excitation of dye molecules, electron injection into Fe 3 O 4 conduction band, and subsequent generation of reactive species highlights a strong potential of Fe 3 O 4 nanoparticles as efficient photocatalyst for removing bromocresol purple dye from water. The results of this study contribute to the development of effective photocatalytic systems for the remediation of dye‐contaminated wastewater.