Sustainable synthesis of silver nanoparticles from Conocarpus seeds for removal of methylene blue.

Abstract

This study introduces a sustainable biological approach for synthesizing silver nanoparticles (AgNPs) using Conocarpus seeds, aimed at improving the adsorption and photocatalytic degradation of methylene blue (MB) in wastewater treatment. The photocatalytic efficiency of AgNPs, synthesized under varying concentrations of silver nitrate (AgNO₃) and pH levels, was evaluated, together with the effectiveness of a photocatalytic reactor. The synthesized samples were characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectroscopy, and atomic force microscopy (AFM). Results showed that MB degradation occurred quickly within the first 50 min, achieving a 99.60% removal efficiency via adsorption and photocatalytic degradation under optimal conditions (pH = 3, 1 g sample) after 1 h. The maximum adsorption capacity reached 49.80 mg·g^-1. Furthermore, the AgNPs demonstrated a significant degradation rate of 99.76% within 2 h under UV light, highlighting the synergistic effects of AgNPs in enhancing both adsorption and photocatalysis. This study not only accentuates the potential of Conocarpus seeds as an eco-friendly precursor for AgNP synthesis but also highlights the applicability of AgNPs in wastewater treatment.