Facile synthesis of mesoporous calcium carbonate particles with finger citron residue as template and their adsorption performances for Congo red

Abstract

Herein, we demonstrate a simple and cost-effective method to prepare the new hierarchically Ni-doped porous CaCO3 monoliths in a large scale by mineralizing finger citron residue templates with a calcium acetate precursor. The morphology, microstructure, and element composition of as-prepared adsorbents are characterized by Scanning Electron Microscope (SEM), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM), and N2 adsorption, respectively. Adsorption performance of anionic dye Congo red was investigated in a batch experiment. The results showed that pseudo-second-order kinetic model and Langmuir adsorption isotherm matched well for the Congo red adsorption. Compared with previously reported adsorbents, due to positive and negative charge effect between Congo red and Ni, Ni-doped porous CaCO3 monoliths demonstrated a superior Congo red dye adsorption capability. The results of the present study substantiate that Ni-doped porous CaCO3 monoliths is a promising adsorbent for the removal of the anionic dyes from wastewater.