Fabrication of attapulgite/carbon composites from spent bleaching earth for the efficient adsorption of methylene blue

Abstract

In this work, one-dimensional attapulgite/carbon composites were prepared by a one-step carbonization process using the residual organic matter of spent bleaching earth as a low-cost available carbon precursor. The obtained composites were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis to confirm the presence of carbonaceous species. The attapulgite/carbon composites can be used as adsorbents for the removal of methylene blue, with a maximum adsorption capacity of 132.72 mg g⁻¹, and the process parameters affecting the adsorption behavior for methylene blue, such as the pH of the solution, calcination temperature and contact time, were also analyzed through batch adsorption processes. It was revealed that attapulgite/carbon composites could be employed as candidates for the removal of cationic dyes.