Bio-synthesis of Pd and Ag nanoparticles supported on celestine and their catalytic performance for reduction of Cr(VI) and methyl orange

Document Type : Research Article

Authors

Department of Chemistry, Faculty of Science, University of Qom, Qom, Iran

10.22091/jaem.2025.11880.1017

Abstract

This study reports the green synthesis of palladium (Pd) and silver (Ag) nanoparticles (NPs) supported on celestine using an aqueous extract of Amaranthus caudatus flowers as both a reducing and stabilizing agent. The synthesized nanocomposites were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and energy-dispersive X-ray spectroscopy (EDS), revealing well-dispersed spherical Pd and Ag NPs with average sizes below 60 nm anchored on the celestine surface. The nanocomposites demonstrated excellent catalytic activity and reusability in the reduction of Cr(VI) ions (using formic acid) and methyl orange (MO) azo dye (using NaBH₄). Notably, Pd NPs/celestine achieved complete reduction of a 10 ppm MO solution in just 30 s, outperforming Ag NPs/celestine (90 s), indicating superior electron transfer efficiency from NaBH₄ to MO molecules. These findings highlight the potential of Pd-based catalysts for efficient pollutant degradation.

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