Facile green synthesis of Sm₂O₃@g–C₃N₄ for enhanced photocatalytic and catalytic degradation of organic pollutant

A simple and easy green synthesis of samarium oxide nanoparticles (Sm₂O₃ NPs) was prepared using Sapindus emarginatus stem bark extract and anchored over graphitic carbon nitride (g-C₃N₄) surface. The synthesized materials characterized by UV–Visible, XRD, SEM, TEM, FT-IR and Raman spectroscopy ensured the development of Sm₂O₃ NPs anchored over the g-C₃N₄ surface. The prepared catalyst was utilized for chromium VI (Cr VI) and 2-chloro phenol (2-CP) degradation through visible light photocatalysis. The optimization of operational parameters, like the effect of catalyst dosage, H₂O₂ concentration and slurry pH, was performed. The results exhibited that compared to pristine g-C₃N₄, photocatalytic efficacy was enhanced two-fold in Sm₂O₃@g–C₃N₄. From the varied Sm₂O₃ content of 5; 10; and 20%wt., it was also found that the highest photoactivity was achieved by the composite having 10%wt. of Sm₂O₃ content. The high effectivity was showed by degradation efficiency of 95% toward Cr(VI) and 82% toward 2-CP. This enhanced photocatalytic performance was originated from characteristics of the hybrid formed between the Sm₂O₃ and g-C₃N₄ so that it improved the effective charge transfer through interfacial interactions between both components. The examination on effect of scavengers suggests that Z-scheme involved in the photocatalytic mechanism which facilitated the efficient separation of the photogenerated electron–hole pairs under visible light illumination.