Against the backdrop of global carbon peaking and carbon neutrality goals, passive radiative cooling (PRC) has become a highly promising zero-energy-consumption technology to alleviate the energy crisis and surging cooling demand. Ideal PRC materials require high reflectance in the solar spectrum (0.4-2.5 μm) to reduce heat absorption and strong emissivity in both atmospheric transparent windows (ATW-I: 8-13 μm; ATW-II: 16-25 μm) to dissipate heat into outer space efficiently. β-Mg2Al4Si5O18 ceramic is theoretically attractive for PRC applications owing to its wide bandgap and rich phonon vibrational modes, yet its practical cooling performance is severely restricted by intrinsic phonon‑polariton resonance that causes obvious emissivity dips and limits heat radiation efficiency.
To break through this long-standing bottleneck, a research team from Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, has innovatively integrated phonon engineering and bandgap engineering to design and synthesize a series of Mg2Al4Si5O18: xY3+ (x = 0%, 2.5%, 5%, 7.5% and 10%) ceramics via a simple high-temperature solid‑state reaction. The researchers systematically investigated the effects of Y3+ doping on crystal structure, lattice distortion, optical bandgap, and spectral properties. Comprehensive characterizations confirm that the optimized 10% Y3+-doped sample achieves an ATW-I emissivity of 97.53%, an ATW-II emissivity of 98.39%, and a Vis-NIR solar reflectance of 94.77%, while the optical bandgap is successfully widened from 3.35 eV to 3.46 eV.
The team published their work in Journal of Advanced Ceramics on April 8, 2026.
"Y3+ doping exerts a dual regulatory effect," explained Prof. Fan Yang, the corresponding author. "On the one hand, it induces lattice distortion, breaks local crystal symmetry, shortens phonon lifetime, and effectively suppresses phonon-polariton resonance, thereby significantly enhancing infrared emissivity in both atmospheric windows. On the other hand, Y3+ is optically inert and widens the bandgap, which preserves and improves solar reflectance to minimize heat absorption under sunlight."
Inspired by the "cooling glass" concept, the team fabricated a practical PRC coating by mixing the ceramic powder with low-melting-point glass. Outdoor cooling tests in Xiamen show that the coating achieves a maximum temperature reduction of 16.5 °C and an average net radiative cooling power of 113.1 W·m-2, outperforming many reported oxide‑based PRC materials. Notably, this ceramic system is composed of earth-abundant, low‑cost elements without precious metals, and the synthesis and coating processes are simple, scalable, and suitable for mass production.
"This work not only solves the performance limitations of pure Mg2Al4Si5O18 ceramics but also provides a universal doping strategy for spectral optimization of inorganic functional materials," added Prof. Heng Chen, co-corresponding author. "Compared with polymer‑based PRC materials, our ceramic coating exhibits better thermal stability, weather resistance, and UV aging resistance, making it ideal for long-term outdoor applications."
This innovation provides a stable, eco-friendly, and low-cost passive cooling solution for buildings, photovoltaic modules, vehicles, and space facilities. It helps reduce the energy consumption of traditional active cooling systems and cut carbon emissions, offering key material support for low‑carbon urban development and global climate change mitigation.
About Author
Dr. Yang Fan(corresponding author), Chinese Academy of Sciences Fujian Institute of Research on the Structure of Matter, researcher, team leader (Group of Rare Earth Nuclear Security Materials and Rare Earth Secondary Recycling), doctoral advisor, General Manager of China Rare Earth (Shenzhen) Research Institute and Dual-Use Technology Business Division, Council Member of the Chinese Society of Rare Earths and the Chinese Nuclear Chemical Society.
Dr. Chen Heng (corresponding author), Chinese Academy of Sciences Fujian Institute of Research on the Structure of Matter, associate researcher, master's supervisor, has been selected into the Young Talents Promotion Project of the Chinese Association of Science and Technology, Fujian Provincial High level Talents Class C, and Xiamen High level Talents Class C.
Funding:
This research was supported by the National Natural Science Foundation of China (No.52402093), the Self-deployment Project Research Programs of Haixi Institutes, Chinese Academy of Sciences (No. CXZX-2023-JQ07), the XMIREM Autonomously Deployment Project (No. 2023GG03), Natural Science Foundation of Xiamen (No. 3502Z202472048 and No. 3502Z202573100), and Outstanding Youth Fund of Henan Province (No. 252300421006).
About Journal of Advanced Ceramics
Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen . JAC's 2024 IF is 16.6, ranking in Top 1 (1/34, Q1) among all journals in "Materials Science, Ceramics" category, and its 2024 CiteScore is 25.9 (5/130) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508
