Natural-inspired sustainable cellulose cooling aerogel with hetero-photonic scattering network via hydration of metal-organic frameworks-induced interface assembly for energy saving buildings

Abstract

Passive radiative cooling is a sustainable cooling technology that shows great promise in energy-saving fields. However, simultaneously achieving solar reflectivity and infrared emissivity over 95% performance is hindered by the lack of an efficient micro/nano-structure process technology and by photonic design’s shortcomings in terms of high cost and environmental concerns. Herein, inspired by the structural relationship in the white beetle, a novel cooling cellulose aerogel (MCA) with dual-band solar reflectivity and infrared emissivity was proposed by meticulously manipulating the kinetics of the ice-templating process. A hetero-photonic scattering topology composed of nanoparticles, a nano/micro fibers network, and dual-pores via incorporating ice nucleation modifier of hygroscopic metal-organic frameworks (MOF) (modulation of interaction between cellulose, water, and MOF), reproducing the random and anisotropic optical scattering mechanism of white beetles. Driven by the hydration of MOF-induced ice nucleation in binary nanocellulose suspensions, the nanofibers and nanoparticles can form a heterostructured and interconnected micro/nanonetwork via hydrogen bonding and electrostatic interactions. Compared with the traditional pore structure, the bioinspired MCA exhibited a dual band high solar reflectance of 0.958 and infrared emissivity of 0.95, which results in daytime subambient cooling of 7.1 °C during direct sunlight outdoors. Meanwhile, life cycle assessment demonstrates that the preparation process of MCA exhibits a very low environmental impact and is essential for green production and manufacturing. By demonstrating 40% annual cooling energy savings in China, this work paves the way for high-performance, sustainable cooling materials.

Keywords

Nanocellulose aerogel / Metal-organic frameworks / Hydration / Radiative cooling / Energy saving / Biodegradable

References

[1] Atiganyanun, S., Plumley, J.B., Han, S.J., Hsu, K., Cytrynbaum, J., Peng, T.L., Han, S.M., Han, S.E., 2018. Effective radiative cooling by paint-format microsphere-based photonic random media. ACS Photon. 5, 1181-1187.

[2] Bi, Y.H., Luo, X.Y., Yin, Y.X., Tang, F.J., Sun, H.D., Huang, L.L., Chen, L.H., Li, J.G., 2024. Robust, stable cooling cellulose composite: coupling nano-SiO₂ and cellulose acetate in natural cellulose. Int. J. Biol. Macromol. 277, 133728.

[3] Bu, K.L., Huang, X.Y., Li, X.Y., Bao, H., 2023. Consistent assessment of the cooling performance of radiative cooling materials. Adv. Funct. Mater. 33, 2307191.

[4] Cai, C.C., Liu, T., Meng, X.J., Luo, B., Chi, M.C., Wang, J.L., Liu, Y.H., Zhang, S., Gao, C., Bai, Y.Y., Wang, S.F., Nie, S.X., 2025. Lightweight and mechanically robust cellulosic triboelectric materials for wearable self-powered rehabilitation training. ACS Nano 19, 396-405.

[5] Cai, C.Y., Chen, W.B., Wei, Z.C., Ding, C.X., Sun, B.J., Gerhard, C., Fu, Y., Zhang, K., 2023. Bioinspired “aerogel grating” with metasurfaces for durable daytime radiative cooling for year-round energy savings. Nano Energy 114, 108625.

[6] Cai, C.Y., Wei, Z.C., Ding, C.X., Sun, B.J., Chen, W.B., Gerhard, C., Nimerovsky, E., Fu, Y., Zhang, K., 2022. Dynamically tunable all-weather daytime cellulose aerogel radiative supercooler for energy-saving building. Nano Lett. 22, 4106-4114.

[7] Cai, C.Y., Wei, Z.C., Wang, X., Mei, C.T., Fu, Y., Zhong, W.H., 2018. Novel double-networked polyurethane composites with multi-stimuli responsive functionalities. J. Mater. Chem. A 6, 17457-17472.

[8] Chae, D., Lim, H., So, S., Son, S., Ju, S., Kim, W., Rho, J., Lee, H., 2021. Spectrally selective nanoparticle mixture coating for passive daytime radiative cooling. ACS Appl. Mater. Interf. 13, 21119-21126.

[9] Dong, S.H., Wu, Q., Zhang, W.L., Xia, G.F., Yang, L., Cui, J.X., 2022. Slippery passive radiative cooling supramolecular siloxane coatings. ACS Appl. Mater. Interf. 14, 4571-4578.

[10] Fan, S.H., Li, W., 2022. Photonics and thermodynamics concepts in radiative cooling. Nat. Photon. 16, 182-190.

[11] Fathieh, F., Kalmutzki, M.J., Kapustin, E.A., Waller, P.J., Yang, J.J., Yaghi, O.M., 2018. Practical water production from desert air. Sci. Adv. 4, eaat3198.

[12] Gao, H., Li, Y., Xie, Y.J., Liang, D.X., Li, J., Wang, Y.G., Xiao, Z.F., Wang, H.G., Gan, W.T., Pattelli, L., Xu, H.B., 2024. Optical wood with switchable solar transmittance for all-round thermal management. Compos. Part B Eng. 275, 111287.

[13] Hossain, M.M., Gu, M., 2016. Radiative cooling: principles, progress, and potentials. Adv. Sci. 3, 1500360.

[14] Huang, M.Q., Tang, G.H., Ren, X.J., Sun, Q., Du, M., 2023. Effects of microstructure and moisture content on the radiative properties of porous films for radiative cooling. Sol. Energy 262, 111855.

[15] Li, G.W., Huang, J.W., Zhou, J., Zhang, Y.C., Zhang, C.C., Rao, Z.G., Fei, L.F., 2024. A flame-retardant wood-based composite with magnesium-aluminium layered double hydroxides for efficient daytime radiative cooling. J. Mater. Chem. A 12, 1609-1616.

[16] Li, T., Zhai, Y., He, S.M., Gan, W.T., Wei, Z.Y., Heidarinejad, M., Dalgo, D., Mi, R.Y., Zhao, X.P., Song, J.W., Dai, J.Q., Chen, C.J., Aili, A., Vellore, A., Martini, A., Yang, R.G., Srebric, J., Yin, X.B., Hu, L.B., 2019. A radiative cooling structural material. Science 364, 760-763.

[17] Liu, J.W., Tang, H.J., Jiang, C.X., Wu, S.Q., Ye, L., Zhao, D.L., Zhou, Z.H., 2022a. Micro-nano porous structure for efficient daytime radiative sky cooling. Adv. Funct. Mater. 32, 2206962.

[18] Liu, S.P., Sui, C.X., Harbinson, M., Pudlo, M., Perera, H., Zhang, Z.Z., Liu, R.G., Ku, Z., Islam, M.D., Liu, Y.X., Wu, R.H., Zhu, Y., Genzer, J., Khan, S.A., Hsu, P.C., Ryu, J.E., 2023. A scalable microstructure photonic coating fabricated by roll-to-roll “defects” for daytime subambient passive radiative cooling. Nano Lett. 23, 7767-7774.

[19] Liu, Y.M., Bu, X.H., He, M., Liang, S., Zhou, Y.M., 2022b. Robust passive daytime radiative coolers based on thermally insulating and spectrally selective composite aerogels with designed fiber-reinforced porous architecture. Sol. Energy 247, 564-573.

[20] Mandal, J., Yang, Y., Yu, N.F., Raman, A.P., 2020. Paints as a scalable and effective radiative cooling technology for buildings. Joule 4, 1350-1356.

[21] Peng, Z.C., Zeng, F.R., Zeng, Z.W., Su, P.G., Tang, P.J., Liu, B.W., Zhang, Y., Wang, Y.Z., Zhao, H.B., 2025. Scalable low-carbon ambient-dried foam-like aerogels for radiative cooling with extreme environmental resistance. Adv. Mater. 37, 2505224.

[22] Raman, A.P., Abou Anoma, M., Zhu, L.X., Rephaeli, E., Fan, S.H., 2014. Passive radiative cooling below ambient air temperature under direct sunlight. Nature 515, 540-544.

[23] Rostami, J., Benselfelt, T., Maddalena, L., Avci, C., Sellman, F.A., Cinar Ciftci, G., Larsson, P.A., Carosio, F., Akhtar, F., Tian, W.Q., Wågberg, L., 2022. Shaping 90 wt% NanoMOFs into robust multifunctional aerogels using tailored bio-based nanofibrils. Adv. Mater. 34, 2204800.

[24] Scotti, K.L., Dunand, D.C., 2018. Freeze casting-A review of processing, microstructure and properties via the open data repository. Prog. Mater. Sci. 94, 243-305. FreezeCasting.net.

[25] She, Y.N., Wang, J., Zhu, C.F., Tian, F.Y., Jin, Y.Y., Mao, W., Wu, Y.T., Chen, K., Xu, X.W., 2023. From nature back to nature: spectrally modified poplar and its all-day passive radiative cooling. Ind. Crops Prod. 193, 116242.

[26] Syurik, J., Jacucci, G., Onelli, O.D., Hölscher, H., Vignolini, S., 2018. Bio-inspired highly scattering networks via polymer phase separation. Adv. Funct. Mater. 28, 1706901.

[27] Wang, C.H., Chen, X., Wang, B., Huang, M., Wang, B., Jiang, Y., Ruoff, R.S., 2018. Freeze-casting produces a graphene oxide aerogel with a radial and centrosymmetric structure. ACS Nano 12, 5816-5825.

[28] Wang, T., Wu, Y., Shi, L., Hu, X.H., Chen, M., Wu, L.M., 2021. A structural polymer for highly efficient all-day passive radiative cooling. Nat. Commun. 12, 365.

[29] Wang, Z., Wang, T., Zhu, Q., Ding, Z.Y., Gu, M., Zhang, Y.N., 2025a. Bioinspired design of thermally conductive radiative cooling structure for outdoor electronic devices. Adv. Funct. Mater. 35, 2501646.

[30] Wang, Z.N., Pian, S.J., Ma, Y.G., 2025b. Characterization of radiative cooling materials. Nat. Protoc. 21, 2083-2121.

[31] Wei, J., Chen, H., Liu, J.C., Wang, F.Q., Wang, C.H., 2025. Radiative cooling technologies toward enhanced energy efficiency of solar cells: materials, systems, and perspectives. Nano Energy 136, 110680.

[32] Xiong, L.H., Chen, C.L., Tian, K., Zhang, X.Z., Wen, M., Guo, C., Cheng, M.H., Li, Q.Y., Fu, Q., Deng, H., 2025. Dielectric aggregation-mediated dual-band robust optical performance for low-cost radiative cooling. Adv. Mater. 37, 2504150.

[33] Xiong, L.H., Wei, Y., Chen, C.L., Chen, X., Fu, Q., Deng, H., 2023. Thin lamellar films with enhanced mechanical properties for durable radiative cooling. Nat. Commun. 14, 6129.

[34] Yan, Z.S., Liu, X.Y., Ding, B., Yu, J.Y., Si, Y., 2023. Interfacial engineered superelastic metal-organic framework aerogels with van-der-Waals barrier channels for nerve agents decomposition. Nat. Commun. 14, 2116.

[35] Zhang, E.N., Ma, C., Wang, T.L., Mu, L., Yang, Y.J., Chen, G.Y., 2025. Anisotropic nanocellulose-based aerogels for radiative cooling. Int. J. Biol. Macromol. 295, 139580.

[36] Zhang, Y.T., Dao, L.P., Chen, Y.Y., Pang, J., Wu, S.Y., 2026. Bio-inspired porous-hollow biomass-based microfiber prepared by phase separation evolution for efficient radiative cooling. Adv. Funct. Mater. 36, e10324.

[37] Zhou, S.Y., Kong, X.Y., Zheng, B., Huo, F.W., Strømme, M., Xu, C., 2019. Cellulose nanofiber @ conductive metal-organic frameworks for high-performance flexible supercapacitors. ACS Nano 13, 9578-9586.