The Synthesis and Effect of Silver Nanoparticles on the Adsorption of Cu²⁺ from Aqueous Solutions

• Main Authors: Ghadah M. Al-Senani, Nada Al-Kadhi
• Format: Article
• Language: English
• Published: MDPI AG 2020-07-01
• Series: Applied Sciences
• Subjects: AgNPs; Cu²⁺; green synthesis; adsorption; nanoparticles
• Online Access: https://www.mdpi.com/2076-3417/10/14/4840

The adsorption of Cu²⁺ ions from an aqueous solution using AgNPs synthesized from <i>Convolvulus arvensis</i> leaf extract was investigated. The characterization of AgNPs was investigated before and after the adsorption of Cu²⁺ ions via Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM) analyses. The adsorbent contained various functional groups in addition to the AgNPs, which contributed to the Cu²⁺ ions adsorption. The silver nanoparticle surface consisted of spherical particles and deep pores, which adsorbed numerous Cu²⁺ ions. The influences of dosage, pH, and contact time on adsorption of 10 and 50 mg/L Cu²⁺ at 298 K, and initial Cu²⁺ concentrations at 298 and 323 K were studied. It was found that the highest percentage of Cu²⁺ ions adsorbed from an aqueous solution was 98.99%; the aqueous solution had 10 mg/L of Cu²⁺ ions and 0.2 g of AgNPs, at pH 12 and 298 K. A pseudo-second kinetics model offered the most accurate description of the process of adsorption. The process of Cu²⁺ adsorption more resembled a Langmuir rather than a Freundlich isotherm model, including chemical and physical mixed adsorption (mixed adsorption) processes, and was exothermic and spontaneous.