(MgCoNiCuZn)O-coated ceramic membrane: Preparation, microstructure, and properties

Ceramic pristine membrane was prepared and coated with (MgCoNiCuZn)O slurry by dip-coating procedure. According to the XPS results, the high-entropy oxide was coated effectively on the pristine membrane surface. XRD measurement showed that a single-phase rock-salt structure was obtained in the coated-membrane calcined at 1000 °C. SEM measurements indicated that a uniform coating could be observed on the surface of the coated membranes and EDS exhibited approximately even distribution of five metals. The water contact angle increased when (MgCoNiCuZn)O was coated on the surface of membrane, which was attributed to the high configuration entropy. The porosity of coated membrane changed from 64.7% to 62.2% as the coating number, implying that coating had no significant effect on the porosity of pristine membrane. The coated membrane exhibited a high pure water flux and carbon retention. For the membrane coated with three layers of high-entropy ceramic, the pure water flux and rejection ratio of carbon black reached 706 L m−2 h−1·bar−1 and 96.54%, respectively. The coated membrane also exhibited good long-term stability and corrosion resistance under acidic or alkaline environment.