Preparation of Porous Al–Cu–Fe–Cr Quasicrystalline Samples by Alkaline Leaching for Adsorption and Catalytic Applications

Abstract

This study develops a multifunctional porous quasicrystalline (QC) material from an Al–Cu–Fe–Cr alloy for efficient adsorption and catalytic degradation of Congo Red. By optimizing alkaline leaching conditions, the material’s porosity, surface chemistry, and functional performance were tailored. An Al85Cu6Fe3Cr6(at%) alloy produced by spray forming was leached in 10 M NaOH for 0.5–48 h to selectively dissolve aluminum and expose active sites. A systematic investigation of the structural evolution and surface properties was conducted, and the adsorption capacity and catalytic behavior of the prepared alloys were also evaluated. After 30 min of controlled leaching, an optimal macroporous structure was produced with 10.9% porosity and a positive surface charge of 7.2 mV. This enhances the electrostatic adsorption of CR, achieving 70% removal within 24 h while maintaining QC phases and accessible active sites. The material also demonstrated effective catalytic activity, achieving complete azo-bond cleavage in under 10 min, favored by oxidized Fe/Cr/Cu species.