Selective organic dye adsorption properties of aluminum oxide cluster

Dyeing and printing wastewater is a significant cause of water pollution. Adsorption is considered a highly promising method for removing organic pollutants from wastewater. While aluminum oxide clusters (AlOCs) have recently become a popular research topic, there is a lack of research on the adsorption of organic dyes by AlOCs. This study investigates the adsorption properties of AlOCs and reveals their selective adsorption capability for organic dyes. Specifically, AlOCs exhibit exceptional adsorption efficiency for anionic organic dyes with a linear structure. Notably, the adsorption capacity of AlOCs for methyl orange removal is remarkable, achieving a high removal percentage of 97% and an impressive adsorption capacity of 1346 mg/g. However, the adsorption percentage for the sterically hindered cationic dye, crystal violet, is less than 10%. The process follows the pseudo-second order adsorption kinetics and Langmuir isotherm model, suggesting monolayer, homogeneous, chemisorption. Importantly, the adsorbents display high efficiency and capacity, making them applicable for wide-ranging dye removal.