Preparation of novel (MgCoNiCuZn)O high-entropy ceramic membrane and its dye separation

(MgCoNiCuZn)O high entropy ceramic (HEC) membrane was prepared successfully by phase inversion and calcination, and was used to remove Congo red. Raman spectra and XRD measurements showed complete transformation to single rock salt phase, and EDS exhibited uniform distribution of five metals. The hydrophilicity of HEC membrane became weak due to low free energy which was attributed to the high configuration entropy. The porosity of HEC membrane decreased and densification took place as the temperature enhanced, yielding the increase of bending strength. When the HEC membrane was calcined at 1040 celcius, the pure water flux and Congo red rejection reached 881.5 L/(m2 & BULL;h) and 99.35%, respectively. The HEC membrane exhibited good long-term stability. When continuous filtration was performed for 10 h, the pure water flux ranged from 857.5 to 879 L/(m2 & BULL;h), while Congo red rejection changed from 98.85% to 99.32%. The HEC membrane showed good chemical stability under weakly acidic and strong alkaline conditions.