Controllable synthesis of coral-like hierarchical porous magnesium hydroxide with various surface area and pore volume for lead and cadmium ion adsorption

Hu Zhu; Lu Li; Wendan Chen; Yuejin Tong; Xuesong Wang

doi:10.1016/j.jhazmat.2021.125922

Controllable synthesis of coral-like hierarchical porous magnesium hydroxide with various surface area and pore volume for lead and cadmium ion adsorption

J Hazard Mater. 2021 Aug 15:416:125922. doi: 10.1016/j.jhazmat.2021.125922. Epub 2021 Apr 19.

Authors

Hu Zhu¹, Lu Li¹, Wendan Chen¹, Yuejin Tong¹, Xuesong Wang²

Affiliations

¹ Engineering Research Center of Industrial Biocatalysis, Fujian Province University, Fujian Provincial Key Laboratory of Polymer Materials, College of Chemistry and Materials Science, Fujian Normal University, 32 Shangsan Road, Fuzhou 350007, People's Republic of China.
² Engineering Research Center of Industrial Biocatalysis, Fujian Province University, Fujian Provincial Key Laboratory of Polymer Materials, College of Chemistry and Materials Science, Fujian Normal University, 32 Shangsan Road, Fuzhou 350007, People's Republic of China. Electronic address: wangxs@fjnu.edu.cn.

PMID: 34492854
DOI: 10.1016/j.jhazmat.2021.125922

Abstract

A coral-like hierarchical porous magnesium hydroxide (HPMH) with various surface area and pore volume was controllably prepared using a simple one-step hydrothermal process, for which MgO, water and citric acid were applied. The citric acid (CA), as a structure-directing molecule, is a key factor in regulating the pore structure of HPMH products. With different additive dosages, the nanostructure, surface area and pore volume of HPMH products can be controllably regulated. The MH-CA20 product (prepared in the presence of 20 wt% CA) with high BET surface area (159 m²/g) and pore volume (0.75 cm³/g) was used to investigate the adsorption properties for Pb(II) and Cd(II) ions. The experimental adsorption capabilities of the MH-CA20 for Pb(II) and Cd(II) are respectively 4535 and 3530 mgg^-1, very close to the maximum adsorption capabilities calculated by Langmuir equation (4545 and 3571 mgg^-1). According to the adsorption kinetics and adsorption isotherm data, the adsorption process conforms to the Pseudo-second-order and Langmuir model, indicating that heavy metal ions conduct monolayer chemical adsorption mechanism. Since the preparation of HPMH is simple, low-cost and filtrate recycling, the process can easily be scaled up and could be a good candidate for application in tackling different wastewater.

Keywords: Adsorption; Controllable synthesis; Heavy metal ion; Hierarchical porous structure; Magnesium hydroxide.