Preparation and characterization of nano-galvanic bimetallic Fe/Sn nanoparticles deposited on talc and its enhanced performance in Cr(VI) removal

Abstract

In this study, talc-supported nano-galvanic Sn doped nZVI (Talc-nZVI/Sn) bimetallic particles were successfully synthesized and utilized for Cr(VI) remediation. Talc-nZVI/Sn nanoparticles were characterized by FESEM, EDS, FTIR, XRD, zeta potential, and BET analysis. The findings verified the uniform dispersion of nZVI/Sn spherical nanoparticles on talc surface with a size of 30–200 nm, and highest specific surface area of 146.38 m2/g. The formation of numerous nano-galvanic cells between nZVI core and Sn shell enhanced the potential of bimetallic particles in Cr(VI) mitigation. Moreover, batch experiments were carried out to investigate optimum conditions for Cr(VI) elimination and total Cr(VI) removal was achieved in 20 min using Sn/Fe mass ratio of 6/1, the adsorbent dosage of 2 g/L, initial Cr(VI) concentration of 80 mg/L, at the acidic environment (pH = 5) and temperature of 303 K. Besides, co-existing of metallic cations turned out to facilitate the electron transfer from the nano-galvanic couple of NZVI/Sn, and suggested the revolution of bimetallic particles to trimetallic composites. The aging study of the nanocomposite confirmed its constant high activity during 60 days. The removal reaction was well described by the pseudo-second-order kinetic and the modified Langmuir isotherm models. Overall, due to the synergistic galvanic cell effect of nZVI/Sn nanoparticles and full coverage of active sites by Sn layer, Talc-nZVI/6Sn was utilized as a promising nanocomposite for fast and highly efficient Cr(VI) elimination.

Fe/Au galvanic nanocells to generate self-sustained Fenton reactions without additives at neutral pH

“…These results reveal that the Fe/Au galvanic nanocells can effectively produce the fundamental ingredients (H 2 O 2 and Fe 2+ ions) to trigger the Fenton catalytic pathway with high efficiency in water at neutral pH without any external additives. 54…”

Hexavalent chromium removal from aqueous medium by ternary nanoadsorbent: A study of kinetics, equilibrium, and thermodynamic mechanism

“…Also, the utilization of Sn(II) oxides has demonstrated considerable potential as an effective materials in addressing removal of Cr(VI) in potable water treatment as Sn(II) can provide two electrons (Sn 2+ ->Sn 4+ + 2e − ) for Cr(VI) reduction. Furthermore, considering the low toxicity of tin and the extremely low solubility of tin compounds, the potential existence of dissolved tin in drinking water is not regarded as a significant risk to human health [19]. Numerous experiments have demonstrated the performance of tin for Cr (VI) removal from the water/wastewater [19,20].…”

“…Furthermore, considering the low toxicity of tin and the extremely low solubility of tin compounds, the potential existence of dissolved tin in drinking water is not regarded as a significant risk to human health [19]. Numerous experiments have demonstrated the performance of tin for Cr (VI) removal from the water/wastewater [19,20]. Most of the researcher applied Sn-based nanoparticle for the photocatalytic reduction of aqueous Cr(VI) under visible light.…”

“…Most of the researcher applied Sn-based nanoparticle for the photocatalytic reduction of aqueous Cr(VI) under visible light. Bayat et al reported maximum adsorption capacity 53.52 mg g -1 at acidic environment of pH 5.0 [19]. On the other hand, Kaprara et al observed maximum uptake capacity of around 19 mg g -1 utilizing Sn-based nanoadsorbent in high acidic environment (pH 2.0) [20].…”