Development of highly active, chemically stable and recyclable magnetic nanophotocatalyst based on plasmonic silver nanoparticles and photosensitive trans-3-(trans-4-imidazolyl) acrylic acid molecules

This study relates to the preparation of a novel nanophotocatalyst comprising of plasmonic silver nanoparticle, photosensitive trans-3-(trans-4-imidazolyl) acrylic acid (T3TTIA) and superparamagnetic iron oxide nanoparticles (SPION). This heterogeneous nano-photocatalyst has been synthesized via hydrothermal route where T3TTIA works as a capping agent and linker for SPION and plasmonic Ag NPs, respectively. Structural, morphological, thermal, magnetic, optical, and catalytic properties have been analyzed in detailed. The spinel cubic type structure of nanocrystals of SPION and silver has been confirmed by XRD analysis. XPS analysis has confirmed the presence of Ag-0, Fe3O4, and integral functional group. The strong chemical interaction of localized surface plasmonic Ag nanoparticles and SPION with photosensitive T3TIAA molecule has been revealed by both the IR and XPS analysis. The shape of the final products has been observed as spherical with average particle size of 12 +/- 0.8 nm (with low degree of agglomeration) as analyzed by scanning electron microscope (SEM) and high resolution transmission electron microscope (HR-TEM). The superparamagnetic nature and high thermal stability of the products have been revealed by vibrating sample magnetometry (VSM) and thermogravimetric (TG) analysis, respectively. UV-visible spectrophotometry analysis has confirmed the maximum absorbance peak at similar to 420 nm, indicates as the characteristic peak of surface plasmon resonance (SPR) for silver nanoparticles with a band gap value of 1.43 eV. Furthermore, Brunauer-Emmett-Teller (BET) analysis has demonstrated mesoporous characteristic of the product which follows type IV isotherms with the average surface area and pore size as 250.492 m(2)/g and 6.1442 nm, respectively. The potential catalytic applications of the as-prepared nanocatalysts have been explored for the decolorization of methyl orange (MO), methylene blue (MB), and photo-reduction of 4-nitrophenol (4-NP) under both Visible and UV light irradiations. The catalytic activity of the as-prepared nanocatalyst has been compared with the recent reported magnetic nano-catalysts. The SPION@T3TIAA-Ag nanocatalyst has shown excellent catalytic behavior toward the treatment of the selected industrial dyes and organic pollutant with recovery and reusability capacity up to seven cycles without losing significant catalytic efficiency.

Automated summary

This study successfully synthesized a novel multifunctional nanophotocatalyst, and confirmed its structure, properties, and catalytic activity through a series of analyses and experiments. The potential applications of the nanocatalyst in dye decolorization and organic pollutant treatment were explored.