Synthesis of LaFeO₃/Ag₂CO₃ Nanocomposites for Photocatalytic Degradation of Rhodamine B and <i>p</i>-Chlorophenol under Natural Sunlight

Abstract

Novel LaFeO₃/Ag₂CO₃ nanocomposites are synthesized by co-precipitation method for photocatalytic degradation of Rhodamine B (RhB) and <i>p</i>-chlorophenol under visible light irradiation. Heterostructures between LaFeO₃ and Ag₂CO₃ semiconductors are formed during the synthesis of these nanocomposites. Among the nanocomposites prepared with different ratios of LaFeO₃ and Ag₂CO₃, 1% LaFeO₃/Ag₂CO₃ shows the highest photocatalytic activity for the degradation of RhB. Maximum electron-hole pair decoupling efficiency is observed in 1% LaFeO₃/Ag₂CO₃, which causes the greater activity of the heterostructure. Degradation efficiency of 99.5% for RhB and 59% for <i>p</i>-chlorophenol has been obtained under natural sunlight within 45 min. Interestingly, the stability of Ag₂CO₃ is improved dramatically after making nanocomposite, and no decomposition of the catalyst was observed even after several photocatalytic cycles. Reactive oxygen species scavenging experiments with <i>p</i>-benzoquinone, isopropyl alcohol, and ammonium oxalate suggest that a major degradation process is caused by holes. Degradation of RhB into small organic moieties is detected using LC-MS technique. Further, the efficient mineralization of the degradation products occurs during the catalytic process.