Gang Dong

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.

The high coefficients of thermal expansion (CTEs; α ) of common porcelain tiles result in deformation, cracking and even breakage after prolonged utilization in an underfloor heating system. Cordierite‐based porcelain tiles with low α values have good application potential in underfloor heating systems. Herein, environmentally friendly and low‐cost cordierite‐based porcelain tiles made with desert sand were presented. The bulk density, linear shrinkage, water absorption, CTE, and modulus of rupture were determined to investigate the sintering stage of this desert sand‐based low‐expansion porcelain tiles. Powder X‐ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy analyses were used to characterize the phase changes and microstructures of the materials. The results revealed that mass ratio of SiO ₂ to Al ₂ O ₃ ( m [SiO ₂ /Al ₂ O ₃ ]), mass ratio of MgO to Al ₂ O ₃ ( m [MgO/Al ₂ O ₃ ]), and sintering temperature jointly affected the CTEs of the porcelain tiles. Moreover, the sintering temperature significantly impacted the quantities and morphologies of the cordierite crystals. An increase in the number of columnar‐like cordierite crystals during production resulted in a decreased CTE. The results of this study present an effective technique for preparing low‐CTE porcelain tiles from natural waste materials. These desert sand‐based tiles could be widely applied in underfloor heating systems.