{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T15:52:21Z","timestamp":1788191541374,"version":"build-2803163510"},"reference-count":26,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2023,11,27]],"date-time":"2023-11-27T00:00:00Z","timestamp":1701043200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Chung-Ang University Research Scholarship","award":["P0012453"],"award-info":[{"award-number":["P0012453"]}]},{"name":"Chung-Ang University Research Scholarship","award":["RS-2022-00155175"],"award-info":[{"award-number":["RS-2022-00155175"]}]},{"name":"Korea Institute for Advancement of Technology (KIAT)","award":["P0012453"],"award-info":[{"award-number":["P0012453"]}]},{"name":"Korea Institute for Advancement of Technology (KIAT)","award":["RS-2022-00155175"],"award-info":[{"award-number":["RS-2022-00155175"]}]},{"name":"Ministry of Trade, Industry and Energy (MOTIE, Korea)","award":["P0012453"],"award-info":[{"award-number":["P0012453"]}]},{"name":"Ministry of Trade, Industry and Energy (MOTIE, Korea)","award":["RS-2022-00155175"],"award-info":[{"award-number":["RS-2022-00155175"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>In recent years, many parts of the world have researched the transition to renewable energy, reducing energy consumption and moving away from fossil fuels. Among the studies to reduce energy consumption, passive radiative cooling can reduce the energy used for building cooling, and to improve this, the optical properties of atmospheric window emissivity and solar reflectance must be increased. In this study, hollow yttrium oxide (H-Y2O3) was fabricated using melamine formaldehyde (MF) as a sacrificial template to improve the optical properties of passive radiative cooling. We then used finite-difference time-domain (FDTD) simulations to predict the optical properties of the fabricated particles. This study compares the properties of MF@Y(OH)CO3 and H-Y2O3 particles derived from the same process. H-Y2O3 was found to have a solar reflectance of 70.73% and an atmospheric window emissivity of 86.24%, and the field tests revealed that the temperature of MF@Y(OH)CO3 was relatively low during the daytime. At night, the temperature of the H-Y2O3 film was found to be 2.6 \u00b0C lower than the ambient temperature of 28.8 \u00b0C. The optical properties and actual cooling capabilities of the particles at each stage of manufacturing the hollow particles were confirmed and the cooling capabilities were quantified.<\/jats:p>","DOI":"10.3390\/ma16237373","type":"journal-article","created":{"date-parts":[[2023,11,27]],"date-time":"2023-11-27T07:56:10Z","timestamp":1701071770000},"page":"7373","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Fabrication of Yttrium Oxide Hollow Films for Efficient Passive Radiative Cooling"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-5056-1752","authenticated-orcid":false,"given":"Heegyeom","family":"Jeon","sequence":"first","affiliation":[{"name":"Department of Advanced Materials Engineering, Chung-Ang University, Anseong 17546, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sohyeon","family":"Sung","sequence":"additional","affiliation":[{"name":"Advanced Materials Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-7447-4669","authenticated-orcid":false,"given":"Jeehoon","family":"Yu","sequence":"additional","affiliation":[{"name":"Department of Advanced Materials Engineering, Chung-Ang University, Anseong 17546, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2951-9848","authenticated-orcid":false,"given":"Hyun","family":"Kim","sequence":"additional","affiliation":[{"name":"Advanced Materials Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yong Seok","family":"Kim","sequence":"additional","affiliation":[{"name":"Advanced Materials Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3276-389X","authenticated-orcid":false,"given":"Youngjae","family":"Yoo","sequence":"additional","affiliation":[{"name":"Department of Advanced Materials Engineering, Chung-Ang University, Anseong 17546, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,11,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/j.egypro.2018.10.050","article-title":"Fossil fuel energy consumption in European countries","volume":"153","author":"Martins","year":"2018","journal-title":"Energy Procedia"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"6661","DOI":"10.1038\/s41598-020-63027-2","article-title":"Cool White Polymer Coatings based on Glass Bubbles for Buildings","volume":"10","author":"Nie","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Xie, X., Liu, Y., Zhu, Y., Xu, Z., Liu, Y., Ge, D., and Yang, L. (2022). Enhanced IR Radiative Cooling of Silver Coated PA Textile. Polymers, 14.","DOI":"10.3390\/polym14010147"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"540","DOI":"10.1038\/nature13883","article-title":"Passive radiative cooling below ambient air temperature under direct sunlight","volume":"515","author":"Raman","year":"2014","journal-title":"Nature"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/j.renene.2017.01.018","article-title":"A field investigation of passive radiative cooling under Hong Kong\u2019s climate","volume":"106","author":"Tso","year":"2017","journal-title":"Renew. Energy"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"124350","DOI":"10.1016\/j.energy.2022.124350","article-title":"A dual-layer polymer-based film for all-day sub-ambient radiative sky cooling","volume":"254","author":"Liu","year":"2022","journal-title":"Energy"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"541","DOI":"10.1016\/j.asr.2023.03.004","article-title":"Multilayer nanoparticle-polymer metamaterial for radiative cooling of the stratospheric airship","volume":"72","author":"Fu","year":"2023","journal-title":"Adv. Space Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1111\/ijac.14269","article-title":"Critical thickness of polymer-derived ceramic coatings with particulate fillers","volume":"20","author":"Zhang","year":"2023","journal-title":"Int. J. Appl. Ceram. Technol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"103398","DOI":"10.1016\/j.mtcomm.2022.103398","article-title":"Cost effective 24-h radiative cooler with multiphase interface enhanced solar scattering and thermal emission","volume":"31","author":"Zhang","year":"2022","journal-title":"Mater. Today Commun."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"You, P., Li, X., Huang, Y., Ma, X., Pu, M., Guo, Y., and Luo, X. (2020). High-Performance Multilayer Radiative Cooling Films Designed with Flexible Hybrid Optimization Strategy. Materials, 13.","DOI":"10.3390\/ma13132885"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"111723","DOI":"10.1016\/j.solmat.2022.111723","article-title":"Sub-ambient radiative cooling under tropical climate using highly reflective polymeric coating","volume":"240","author":"Han","year":"2022","journal-title":"Sol. Energy Mater. Sol. 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Cells"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"315","DOI":"10.1126\/science.aat9513","article-title":"Hierarchically porous polymer coatings for highly efficient passive daytime radiative cooling","volume":"362","author":"Mandal","year":"2018","journal-title":"Science"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1016\/j.solener.2023.03.018","article-title":"Scalable fabrication of super-elastic TPU membrane with hierarchical pores for subambient daytime radiative cooling","volume":"256","author":"Song","year":"2023","journal-title":"Sol. Energy"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"e202201842","DOI":"10.1002\/cssc.202201842","article-title":"Passive Daytime Radiative Cooling by Thermoplastic Polyurethane Wrapping Films with Controlled Hierarchical Porous Structures","volume":"15","author":"Park","year":"2022","journal-title":"ChemSusChem"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/j.solmat.2017.04.020","article-title":"Double-layer nanoparticle-based coatings for efficient terrestrial radiative cooling","volume":"168","author":"Bao","year":"2017","journal-title":"Sol. Energy Mater. Sol. Cells"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"e2022GL102256","DOI":"10.1029\/2022GL102256","article-title":"Cloud-Surface Coupling Alters the Morning Transition from Stable to Unstable Boundary Layer","volume":"50","author":"Su","year":"2023","journal-title":"Geophys. Res. Lett."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"133093","DOI":"10.1016\/j.cej.2021.133093","article-title":"Tailoring body surface infrared radiation behavior through colored nanofibers for efficient passive radiative heating textiles","volume":"430","author":"Li","year":"2022","journal-title":"Chem. Eng. J."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"43553","DOI":"10.1021\/acsami.0c09374","article-title":"Selectively Enhancing Solar Scattering for Direct Radiative Cooling through Control of Polymer Nanofiber Morphology","volume":"12","author":"Kim","year":"2020","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"106949","DOI":"10.1016\/j.compositesa.2022.106949","article-title":"Hollow Core-Shell Particle-Containing Coating for Passive Daytime Radiative Cooling","volume":"158","author":"Hu","year":"2022","journal-title":"Compos. Part A Appl. Sci. Manuf."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"141652","DOI":"10.1016\/j.cej.2023.141652","article-title":"Hybrid emitters with raspberry-like hollow SiO2 spheres for passive daytime radiative cooling","volume":"459","author":"Park","year":"2023","journal-title":"Chem. Eng. J."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1016\/j.solener.2022.05.023","article-title":"Nanocomposite coatings with plasmonic structural colors for subambient daytime radiative cooling","volume":"240","author":"Jin","year":"2022","journal-title":"Sol. Energy"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"113710","DOI":"10.1016\/j.optmat.2023.113710","article-title":"Enhanced passive radiative cooling coating with Y2O3 for thermal management of building","volume":"138","author":"Luo","year":"2023","journal-title":"Opt. Mater."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"7721","DOI":"10.1021\/ic100430g","article-title":"Facile Synthesis and Luminescence of Uniform Y2O3 Hollow Spheres by a Sacrificial Template Route","volume":"49","author":"Jia","year":"2010","journal-title":"Inorg. Chem."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/16\/23\/7373\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:31:35Z","timestamp":1760131895000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/16\/23\/7373"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,11,27]]},"references-count":26,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2023,12]]}},"alternative-id":["ma16237373"],"URL":"https:\/\/doi.org\/10.3390\/ma16237373","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,11,27]]}}}