Layered ammonium vanadate nanobelt as efficient adsorbents for removal of Sr2+ and Cs+ from contaminated water

Heng Zhang; Chunmin Li; Xujie Chen; Hao Fu; Yanliang Chen; Shunyan Ning; Toyohisa Fujita; Yuezhou Wei; Xinpeng Wang

doi:10.1016/j.jcis.2022.01.164

Layered ammonium vanadate nanobelt as efficient adsorbents for removal of Sr²⁺ and Cs⁺ from contaminated water

J Colloid Interface Sci. 2022 Jun:615:110-123. doi: 10.1016/j.jcis.2022.01.164. Epub 2022 Jan 29.

Authors

Heng Zhang¹, Chunmin Li², Xujie Chen¹, Hao Fu¹, Yanliang Chen³, Shunyan Ning¹, Toyohisa Fujita¹, Yuezhou Wei⁴, Xinpeng Wang⁵

Affiliations

¹ Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, 100 Daxue East Road, Nanning, 530004, PR China.
² College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252000, China.
³ Shanghai Institute of Measurement and Testing Technology (SIMT), No.1500 Zhang heng Road, Pudong New Area, Shanghai, China.
⁴ School of Nuclear Science and Technology, University of South China, Hen Yang, 421001, China.
⁵ Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, 100 Daxue East Road, Nanning, 530004, PR China. Electronic address: wangxinpeng@gxu.edu.cn.

PMID: 35124499
DOI: 10.1016/j.jcis.2022.01.164

Abstract

In this study, a layered ammonium vanadate (NH₄V₄O₁₀) nanobelt adsorbent was synthesized by a facile hydrothermal method to remove Sr²⁺ and Cs⁺ from contaminated water. The NH₄V₄O₁₀ nanobelt was texturally and morphologically characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman, thermogravimetric differential thermal analyzer (TG-DSC), Brunauer- Emmett-Teller (BET), and X-ray photoelectron spectroscopy (XPS) both before and after adsorbing Sr²⁺ and Cs⁺. The results showed that the NH₄V₄O₁₀ nanobelt exhibited the optimal morphological structure with a 2:1 ratio of NH₄VO₃:dipropylamine. In the lattice of the adsorbent, the horizontal distance between oxygen atoms was 0.55 nm, the vertical distance between vanadium was 0.35 nm, and the layer distance of the adsorbent was 0.931 nm. The structure characterization indicated the VO₆ octahedron formed a basic framework through sharing connected vertices. Adsorption mechanism studies indicated that ion exchange was the main adsorption mechanism for removing Sr²⁺ and Cs⁺. Batch experiments revealed that the adsorption capacity for Sr²⁺ was 192.52 mg/g under a pH of 2. Similarly, the adsorption capacity for Cs⁺ was 251.09 mg/g when the pH was 5. The adsorption kinetics and adsorption isotherms data were in accordance with the pseudo-second-order kinetic model and Langmuir model, respectively. Adsorption isotherms results also indicated that the adsorption of Sr²⁺ and Cs⁺ was endothermic (ΔH_Sr⁰ = 3.6 kJ/mol, ΔH_Cs⁰ = 29.1 kJ/mol) and increased entropy (ΔS_Sr⁰ = 29.15 J/molK, ΔS_Cs⁰ = 160.38 J/molK). Finally, the structure of the adsorbent, the adsorption performance and mechanism, and the interpretation of selective adsorption were also calculated by DFT method at the molecular level and the results were consistent with the experimental data.

Keywords: DFT calculations; Ion exchange; NH(4)V(4)O(10) nanobelt; Nuclear wastewater; Sr(2+) and Cs(+) removal.