Defect engineering in high‐entropy ceramics glaze enable infrared emissivity and antibacterial properties

Abstract Making high‐entropy oxides (HEOs) powder practical is a great challenge. Despite recent advancements, the practicality of high‐entropy ceramics (HECs) glazes for portable infrared radiation and antimicrobial remains doubtful due to its numerous defects. Here, we report the doping of Zn or Cu in quinary HEOs system ((Cr, Mn, Fe, Co, Ni) 3 O 4 ) to form hexanary HEOs systems ((Cr, Mn, Fe, Co, Ni, Zn) 3 O 4 or (Cr, Mn, Fe, Co, Ni, Cu) 3 O 4 ), which demonstrate promising efficiency in terms of infrared emissivity. The impact of defects (oxygen vacancies) on the electronic and band structure of HEOs and their infrared emissivity are fundamentally elucidated. Notably, we introduced HEOs into ceramic glaze for the first time, and the designed HECs glaze enables higher infrared radiation capability, with infrared emissivity of 85.47% and 91.27% µm in wavelength ranges of 0.78–2.5 and 2.5–16. The HECs glazes also exhibit excellent antibacterial effects against Escherichia coli and Staphylococcus aureus . Essentially, orbital hybridization induced by high‐entropy strategy can effectively enhance the probability of electron transitions, thereby improving the ability to absorb and emit infrared radiation. The introduction of multivalent metal creates numerous oxygen vacancies, which narrows the band gap and makes it easier for electrons to cross energy levels and thus participate in the infrared radiation process. This work introduces an approach for enhancing the infrared radiation and antibacterial properties of HECs glazes based on high‐entropy effects and defect engineering, providing a platform for designing ceramic glazes for thermal management and biology.