Facile and Widely Applicable Route to Self-Adaptive Emissivity Modulation: Energy-Saving Demonstration with Transparent Wood

Xin Hu; Wei Cai; Yingbo Zhang; Shuo Shi; Yang Ming; Rujun Yu; Daming Chen; Mengyan Yang; Faming Wang; Hongyu Yang; Chi-Wai Kan; Nuruzzaman Noor; Bin Fei

doi:10.1021/acs.nanolett.3c03711

Facile and Widely Applicable Route to Self-Adaptive Emissivity Modulation: Energy-Saving Demonstration with Transparent Wood

Nano Lett. 2024 Jan 17;24(2):657-666. doi: 10.1021/acs.nanolett.3c03711. Epub 2024 Jan 5.

Authors

Xin Hu^{1

2}, Wei Cai^{1

2}, Yingbo Zhang³, Shuo Shi⁴, Yang Ming¹, Rujun Yu^{1

2}, Daming Chen¹, Mengyan Yang^{1

2}, Faming Wang⁵, Hongyu Yang⁶, Chi-Wai Kan¹, Nuruzzaman Noor^{1

2}, Bin Fei^{1

2}

Affiliations

¹ Materials Synthesis and Processing Lab, School of Fashion and Textiles, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR 999077, China.
² Research Centre for Resources Engineering towards Carbon Neutrality, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR 999077, China.
³ Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR 999077, China.
⁴ Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR 999077, China.
⁵ Department of Biosystems Engineering, Faculty of Bioscience Engineering, KU Leuven, Leuven 3001, Belgium.
⁶ College of Materials Science and Engineering, Chongqing University, Shazhengjie 174, Shapingba, Chongqing 400030, China.

PMID: 38180824
DOI: 10.1021/acs.nanolett.3c03711

Abstract

The cooling power provided by radiative cooling is unwanted during cold hours. Therefore, self-adaptive regulation is desired for radiative cooling, especially in all-weather applications. However, current routes for radiative cooling regulation are constrained by substrates and complicated processing. Here, self-adaptive radiative cooling regulation on various potential substrates (transparent wood, PET, normal glass, and cement) was achieved by a Fabry-Perot structure consisting of a silver nanowires (AgNWs) bottom layer, PMMA spacer, and W-VO₂ top layer. The emissivity-modulated transparent wood (EMTW) exhibits an emissivity contrast of 0.44 (ε_8-13-L = ∼0.19 and ε_8-13-H = ∼0.63), which thereby yields considerable energy savings across different climate zones. The emissivity contrast can be adjusted by varying the spinning parameters during the deposition process. Positive emissivity contrast was also achieved on three other industrially relevant substrates via this facile and widely applicable route. This proves the great significance of the approach to the promotion and wide adoption of radiative cooling regulation concept in the built environment.

Keywords: Emissivity modulation; Energy saving; Fabry−Perot resonator; Radiative cooling; Transparent wood.