ENHANCED PHOTODEGRADATION OF 2,4-DICHLOROPHENOXYACETIC ACID BY THE HETEROJUNCTION OF TiO 2 AND Fe-MCM 41 MATERIAL

Tóm tắt

The aim of this study was to synthesize the TiO₂/Fe-MCM-41 heterojunction material using the ultrasonic method for the photodegradation of 2,4- dichlorophenoxyacetic acid (2,4-D) under light irradiation. The synthesized materials were characterized using various techniques, including XRD, FE-SEM, UV-Vis DRS, and EDX. These analyses confirmed that TiO₂ particles were uniformly dispersed on the Fe-MCM-41 support. The integration of TiO₂ with Fe-MCM-41 enhanced visible light absorption, which in turn improved photocatalytic activity under light irradiation. Among the tested conditions, the optimal performance was observed with a TiO₂ loading of 30% (corresponding to a mass-to-volume ratio of 0.5g/L), an initial 2,4-D concentration of 40ppm, a pH of 4.2, and an illumination time of 210 minutes. Under these conditions, the photodegradation efficiency exceeded 97%. Additionally, radical scavenging experiments indicated that superoxide radicals (O₂•⁻), hydroxyl radicals (•OH), and photogenerated holes (h⁺) played critical roles in the photocatalytic degradation process. The TiO₂/Fe-MCM-41 catalyst also demonstrated stable performance over four consecutive cycles, highlighting its potential for repeated use in photocatalytic applications.