Hierarchical CeVO4 hollow microspheres to enable high-efficiency Pb2+ adsorbents

Abstract

Developing high-efficiency adsorbents through a simple, eco-friendly and green synthetic strategy remains an ongoing challenge. Herein, hierarchical nanoflake-assembled hollow microspheres of CeVO₄ (NFHM-CeVO₄) were prepared via a facile hydrothermal method. The as-prepared hierarchical CeVO₄ hollow microspheres possess high specific surface areas (104.68 m² g⁻¹), and were evaluated for the adsorption of Pb²⁺ in aqueous solutions. The adsorption performance of NFHM-CeVO₄ for Pb²⁺ aqueous solutions was thoroughly investigated, including the adsorption kinetics, thermodynamics, and influencing factors. The adsorption kinetics data and experimental adsorption data were described by the pseudo-second-order kinetics model and Langmuir adsorption isotherm, with a maximum adsorption capacity of 487.65 mg g⁻¹. Temperature-dependent adsorption results indicated that the adsorption process was thermodynamically favorable and spontaneous. The Pb²⁺ adsorption is mainly driven by electrostatic attraction and formation of chemical bonds. With a higher adsorption efficiency than many other materials, NFHM-CeVO₄ could be a promising adsorbent for the Pb²⁺ removal from wastewater. This work broadens the application field of CeVO₄ materials and offers a novel approach to develop high-efficiency adsorbents for the removal of Pb²⁺ contaminants.