Comparative Study of Catalytic Activity of Recyclable Au/Fe 3 O 4 Microparticles for Reduction Of 2,4-Dinitrophenol and Anionic, Cationic Azo Dyes

• Published in: ChemistryOpen (Weinheim) 2024-09, Vol.13 (9), p.e202300297
• Main Authors: Batsukh, Ikhbayar, Khishigjargal, Tegshjargal, Dembereldorj, Uuriintuya, Sambuu, Munkhtsetseg, Ganbold, Erdene-Ochir, Norov, Erdene
• Format: Article
• Language: English
• ISSN: 2191-1363; 2191-1363
• DOI: 10.1002/open.202300297

We synthesized Au/Fe O microparticles. Initially, citrate-capped Fe O micro-sized particles were synthesized by the co-precipitation method with an excess amount of trisodium citrate. Gold ions were reduced on the surface of citrate-capped Fe O and grew as gold sub-microparticles with an average diameter of 210 nm on the surface. The characteristic SPR peak of gold nanoparticles on the surface of Fe O was detected at 584 nm, whereas the absorption in the near-infrared region was increased. SEM images has proved that the synthesized Au/Fe O composite microparticles has an average diameter of 1.7 micrometers. The results of XRD patterns proved the existence of both crystal phases of Fe O and Au particles. To investigate the catalytic activity, the reaction rate constant of reduction of 2,4-dinitrophenol (2,4-DNP) and degradation of Congo red (CR), and methylene blue (MB) with NaBH4 in the presence of Au/Fe O catalyst was monitored by UV-Vis spectroscopy. The initial reaction rate constant calculated from the change in characteristic peak absorptions of 2,4-dinitrophenol was 3.97×10  s , while the reaction rate constants for the degradation of CR and MB were 9.72×10  s and 14.25×10  s respectively. After 5 cycles, Au/Fe O microparticles preserved 99 % of the reaction rate constant, exhibiting considerable recycling efficiency in the reduction of nitro groups.