Green synthesis of Ag/AgCl nanoparticles using Jatropha seed extract for photocatalytic degradation and antibacterial treatment of petroleum industry wastewater

Abstract This study introduces a sustainable method for synthesizing silver nanoparticles (Ag NPs) and silver/silver chloride nanoparticles (Ag/AgCl NPs). Jatropha seed extract serves as a natural reducing and stabilizing agent. The key innovation lies in the pH-dependent control of nanoparticle composition and size. This approach enables an eco-friendly and scalable synthesis. Structural analysis confirmed the formation of Ag NPs at pH 7, while Ag/AgCl nanocomposites were obtained at pH 5. Particle size analysis revealed a strong correlation between size, pH, and slurry concentration. The synthesized Ag/AgCl NPs exhibited enhanced photocatalytic degradation of methylene blue under visible light due to improved charge separation. The reaction followed pseudo-first-order kinetics, with a rate constant of 0.00318 min⁻ 1 (R 2 = 0.97758). Antibacterial testing in real petrochemical wastewater confirmed a 92% reduction in bacterial CFU/ml at a 1% slurry concentration. This study highlights pH-controlled green synthesis as a cost-effective environmental solution. Ag/AgCl NPs have been demonstrated to effectively treat real petrochemical wastewater. This approach provides dual benefits including pollutant degradation and microbial control. These findings support sustainable solutions for industrial effluent treatment, water purification, and green nanotechnology.