Green hydrothermal synthesis of Aralia elata leaf extracts functionalized Ag/Au nanomaterials and their dye removal application

Abstract AgNPs and AuNPs typically exhibit special physical and chemical properties, including antibacterial, catalytic, adsorption, optical, and coating properties. This paper uses the leaf extract of the wild plant Aralia elata as the raw material and adopts the green hydrothermal synthesis method to optimize the preparation of AE-NPs functionalized nanomaterials. These materials have the potential for efficient utilization of wild plant resources, with the prospect of high-value utilization of wild plant resources. The peak shapes of AE-AgNPs and AE-AuNPs at 445 nm and 520 nm were confirmed by Uv-vis characterization. SEM and TEM confirmed that both AE-AgNPs and AE-AuNPs exhibited spherical structure, with average particle sizes of 13.99 nm and 14.62 nm; EDS confirmed that AE-NPs contained Ag and Au elements; XRD confirmed that AE-NPs contain metallic elemental crystal structures of Ag and Au. TGA indicates that the AE leaf extract on the surface of nanomaterials modifies their structure. FTIR demonstrates that there is a coating layer of AE leaf extract on the surface of NPs. The leaf extract of Aralia elata could be used as the reducing agent and stabilizer to prepare functionalized nanomaterials, AE-AgNPs, and AE-AuNPs. Dye adsorption experiments confirmed that AE-AgNPs and AE-AuNPs have high-efficiency dye removal properties, and the adsorption processes belong to second-order kinetics. The adsorption capacities of AE-AgNPs and AE-AuNPs for MB dye reached 13.26 mg·g −1 and 27.47 mg·g −1 ; for SY dye, they reached 8.10 mg·g −1 and 13.14 mg·g −1 . MB adsorption process tends to Freundlich multilayer; the SY adsorption process tends to Langmuir monolayer.