Green synthesis of AgNPs–gum rosin–acrylamide nanocomposites using Azadirachta indica extract for adsorption-based dye removal and soil water retention towards SDG6

Silver nanoparticles (AgNPs) were produced from Azadirachta indica leaves' extracts and incorporated into gum rosin and acrylamide to produce agricultural or environmental nanocomposite materials. Results showed that X-ray diffraction (XRD) analysis as well as transmission electron microscopy (TEM) provided evidence that the AgNPs produced are crystalline in nature and have an average particle size of ∼23 nm and a spherical shape. The synthesized nanocomposite exhibited more than 90% adsorption-based removal of malachite green (MG) dye under optimized conditions. Moisture retention increased in both clay and sandy loam soils when 2.0 g of the nanocomposite was added; the clay soil surged from 0.107 g/g to 0.14 g/g, whereas sandy loam soil increased from 0.1 g/g to 0.2 g/g after 25 days of evaluation. The Thermal analysis demonstrated that the nanocomposite materials displayed improved thermal stability, losing less than 33.4% of their mass at 367.6 °C, as measured using thermogravimetric analysis (TGA). The results demonstrate that AgNPs nanocomposites synthesized using green chemistry methods may be effective for use in wastewater treatment, microbial inhibition, and soil moisture management, aligning with SDG 6 (Clean Water and Sanitation). The developed biodegradable nanocomposite exhibited multifunctional behavior by simultaneously providing efficient adsorption-based dye removal and enhanced soil moisture-retention capability.