Rare earth tungstate high-entropy ceramic powders containing holmium with broad-spectrum antibacterial and antiviral activity

A2W3O12-type (A=La, Sm, Eu, Gd, RE) rare earth tungstate high-entropy ceramic powder with a positively charged surface was fabricated by a high-temperature solid-phase method, and its antibacterial and antiviral properties were evaluated for the first time. Changes in the antibacterial and antiviral activity and ionic solubility of these compounds induced by changing the RE element at the A-position were investigated. The A2W3O12 high-entropy ceramic powder was a stable surface antibacterial material. Its antimicrobial properties are not affected by light and environmental acids and bases. The (La0.2Sm0.2Eu0.2Gd0.2Ho0.2)2W3O12 high-entropy ceramic powder had the best antibacterial performance in the absence of light, and the killing rate was more than 99.9% for both Staphylococcus aureus and Escherichia coli. On this basis, the animal viruses H1N1 influenza virus (enveloped) and EV71 enterovirus (nonenveloped) were selected for antiviral testing, and the survival rate of both viruses decreased by more than 99% within 2 h. The powder was evaluated for ion solubilization under acidic and alkaline service conditions, showing low ion solubilization and superior environmental suitability.