Magnetic Iron Oxide Nanoparticles Modified with Moringa Seed Proteins for Recovery of Precious Metal Ions

Abstract

Precious metals are highly demanded economic value metals that require to be recovered from industrial wastes and electronic used products (e-waste). They are such as gold (Au) as well as Platinum Group Metals (PGMs) for instance palladium (Pd) and platinum (Pt). The study was conducted to test the magnetic iron oxide nanoparticles modified with Moringa oleifera seed proteins as adsorbent for recovery of Au(III), Pd(II) and Pt(IV) from aqueous solutions. Different functional groups responsible for adsorption, morphology, thermal stability, and surface charges of the nanoparticles were characterized with FTIR, SEM, TGA and Zeta potential respectively. Batch adsorption method was used, and precious metal ions percentage recovery was measured using ICP-OES. The effects of pH, initial adsorbate concentration, adsorption agitation time and adsorbent dosage were studied at room temperature of 25˚C. Au(III) yielded a maximal recovery of 99.8%, followed by Pt(IV) with 87.7%, then Pd(II) with 72.7% at a pH 2.5, 10 mg/L initial adsorbate concentration, 120 minutes agitation time and 0.065 g adsorbent dosage. These results suggested that modified iron oxide nanoparticles were effective in selective recovery of the precious metal ions.

Synergistic Antiviral Effects of Metal Oxides and Carbon Nanotubes

“…From Figure 4 c, the stretching bands at 3406 (1) and 3147 (2) cm −1 belonged to the O–H functional groups. The sharp peak at 1400 cm −1 (4) and a low intensity peak observed at 1633 cm −1 (3) were due to the H–O–H adsorbed water frequency, as reported before [ 42 ]. The peak at 1093 cm −1 (5) was due to OH stretching vibration [ 42 ].…”

“…The sharp peak at 1400 cm −1 (4) and a low intensity peak observed at 1633 cm −1 (3) were due to the H–O–H adsorbed water frequency, as reported before [ 42 ]. The peak at 1093 cm −1 (5) was due to OH stretching vibration [ 42 ]. Additionally, there was a broad and one sharp band in the range of 536 (6) and 457 (7) cm −1 , respectively, which were attributed to the Fe–O bonds [ 43 , 44 ] and these bands were also observed in Figure 4 d as (3) and (4), respectively.…”

Sub-acute and chronic toxicity of silver nanoparticles synthesized by Azadirachta indica extract

“…The biomolecules responsible for reducing Ag+ ions and capping the bio-fabricated AgNPs were presented at different functional groups such as the alkane, alkene, amine, and carboxylic acid. They have been recently reported to be major reducing agents in the biosynthesis of silver nanoparticles (Amuanyena et al, 2019). This in addition plays majorly the role of indicator of the presence of residues of plant phytochemicals in the synthesized silver nanoparticles, .…”

“…The results depict the presence of hydroxyl /alcohol groups at 3679.9 cm −1 , alkyne C-H, saturated aliphatic groups of alkane and hydrocarbons including methyl C-H at 2935.5 cm −1 and methylene at C-H 1595.0 cm −1 , aliphatic fluoro compounds at 1143.7 cm −1 and aliphatic phosphates at 1112.9 cm −1 . This was compared to the study of Tensingh (2017) and Amuanyena et al (2019).…”

Synthesis of cobalt loaded double perovskite Sr 2 TiFeO 6 ‐δ ( STF ) as a stable catalyst for enhanced hydrogen production via methane decomposition

“…63 The peak in 1442 to 1456 cm À1 region corresponds to H O H stretching of adsorbed water. 64 The additional peak observed at 1114 cm À1 for 5% Co/STF corresponds to Co 2+ bridging vibration in tetrahedral coordination. 65…”