Mechanism of novel MoS2-modified biochar composites for removal of cadmium (II) from aqueous solutions

Abstract

The purpose of this study was to develop a MoS₂-impregnated biochar (MoS₂@BC) via hydrothermal reaction for adsorption of cadmium (Cd) from an aqueous solution. The prepared adsorbents were characterized, and their abilities to remove Cd(II) were evaluated. The Langmuir and pseudo-second-order models better described the removal of Cd(II) by MoS₂@BC. The prepared MoS₂@BC exhibited excellent monolayer adsorption capacity. The S-containing functional groups on MoS₂@BC enhanced the adsorption of Cd(II). Multiple Cd(II) sorption mechanisms were identified; including Cd(II)-π interactions, ion exchange, electrostatic interaction, and complexation. The dominant mechanism involved Cd-O (38.3%) bonds and Cd-S complexation (61.7%) on MoS₂@BC. The as-prepared MoS₂@BC is both economical and efficient, making it an excellent material for environmental Cd(II) remediation.