Abstract: In the biomimetic field, it is desirable yet challenging to replicate the same solar spectrum as leaves, particularly in the visible band. The green peak at 550 nm is crucial for spectral detection, as it influences leaf similarity and visible-spectrum match performance. Herein, highly visible spectral similarity and green peak position with almost zero deviation from that of leaves are realized. Comparative experiments and characterization indicate the successful intercalation of organic pigment anions into Mg/Al-layered double hydroxides (Mg/Al-LDHs). Furthermore, a high spectral angle cosine (cosθ) of 97.7 % is yielded for pigments within 400-2500 nm. The corresponding biomimetic leaves (BLs) show a visible cosθ of 99.0 %, and the green peak position is precisely located at 550 nm. Moreover, the visible spectral similarities compared with eight leaves are all above 90.0 %, demonstrating a good generality. The performance should be attributed to electrostatic adsorption between the intercalated pigment anions and exposed cations on the Mg/Al-LDH layers. Meanwhile, the strong electrostatic adsorption ensures the heat stability of the intercalated species. This work presents pigments and BLs that accurately match the chromaticity and visible spectrum of leaves.

Key words: Biomimetic leaves, Visible band, Reflective spectra, Green peak, Electrostatic adsorption