Investigation of the usability of Ce- and N-doped hybrid carbon quantum dots for the removal of neodymium ions

Abstract This study evaluates Ce and N doped carbon quantum dots (CQDs) integrated into hydrogel matrices for neodymium (Nd) ion removal from aqueous solutions. CQDs were synthesized using Agaricus Bisporus mushrooms and incorporated into hydrogels with 1% mushroom loading, achieving a maximum adsorption capacity of 78.55 mg/g under 180 min, pH 5.0, 298 K, and 1 g/L solid-to-liquid ratio. Adsorption followed the Langmuir isotherm and pseudo-second-order kinetics, with thermodynamic analyses confirming a spontaneous and endothermic process. These findings demonstrate the effectiveness of Ce-N/CQDs@HG composites for environmental remediation.