High adsorption capacity for dye removal by CuZn hydroxyl double salts

Abstract

CuZn hydroxyl double salts (CuZn–HDS) were prepared using the same synthesis method of LHZS by adding a copper source. When tested as adsorbents for methyl orange (MO) removal, CuZn–HDS exhibited better performance than layered hydroxyl zinc salt (LHZS). CuZn-1 had a surface area of 33.8 m² g⁻¹ and displayed a maximum adsorption capacity of 847 mg g⁻¹ for MO, which made it a potentially attractive adsorbent in water purification. The adsorption process followed a pseudo-second-order kinetic model, and the adsorption isotherm has been satisfactorily fitted using the Langmuir model. The adsorption mechanism for MO on CuZn-1 was also investigated.