THE SYNTHESIS Ag/Fe3O4 NANOPARTICLES USING GUAVA LEAF EXTRACT (PSIDIUM GUAJAVA L.) AND ITS APPLICATION FOR CATALYTIC REDUCTION OF METHYLENE BLUE AND RHODAMINE B

This article presents a study on green synthesis Ag/Fe3O4 using guava leaf extract and its application for catalytic reduction of methylene blue (MB) and rhodamine B (RhB) with NaBH4. The synthesized material was characterized using X-ray diffraction (XRD), EDX spectroscopy, and SEM images. The results of analyzing the physicochemical properties of materials showed that the obtained material consisted of two nano-sized phases: Ag (d = 20 nm) and Fe3O4 (d = 12 nm). The synthesized material was used as a catalyst for the reduction of methylene blue and rhodamine B with NaBH4. It was shown that Ag/Fe3O4 material increases the reduction rate of methylene blue and rhodamine B by approximately 26.3 times and 57.8 times compared to without a catalyst. The results showed that the Fe3O4 phase acts as a carrier, determining the magnetism, while the Ag phase acts as the catalytic center, determining the catalytic activity of the material. The influence of synthesis conditions on the catalytic activity of Ag/Fe3O4 materials was studied. It was shown that Ag/Fe3O4 materials were synthesized under the following conditions: 12.5 g guava leaves/200 mL distilled water, extraction time: 20 min, extraction temperature: 70 °C, extract volume of 10 mL/50 mL of 5 mM AgNO3 solution at 40 °C for 30 min have the best catalytic activity. The reduction rate constants of methylene blue and rhodamine B with NaBH4 in the presence of Ag/Fe3O4 are 0.3534 min-1 and 0.4886 min-1, significantly higher than similar catalysts. The catalyst was recyclable for 3 catalytic cycles with a drop from 92.8% (91.6%) to 75.2% (74.5%) in the removal efficiency for MB (RhB). For citation: Vu Thi Duyen, Dinh Van Tac The synthesis Ag/Fe3O4 nanoparticles using guava leaf extract (Psidium guajava L.) and its application for catalytic reduction of methylene blue and rhodamine B. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2025. V. 68. N 4. P. 41-48. DOI: 10.6060/ivkkt.20256804.7133.