Toward Recyclable, Luminescent Transparent Wood Film via Synergistic Light Responses of Lignocellulose and Phosphors for Plant Growth Lighting and Optical Thermometer

Abstract

Regarding global energy scarcity issues, establishing sustainable plant production systems and promoting smart agriculture has become imperative. Herein, considering the important role played by plant lighting and temperature sensing in smart agriculture, an innovative recyclable luminescent and transparent wood film (LTWF) is constructed and fabricated incorporating lignocellulose framework and phosphors to establish a bifunctional platform including plant growing lighting and optical thermometer. Specifically, benefiting from the synergistic light response of lignocellulose (blue emission 462 nm) and phosphor (red emission 616 nm), the tunable LTWF emission spectrum is aligned with the absorption spectra of the plant chlorophylls, carotenoids, and photosensitive pigment Pr, demonstrating its potential for plant growth lighting. Moreover, the distinct thermo-responsive spectral signals based on the dual emission of LTWF are assessed for optical thermal sensing applications using fluorescence intensity ratio (FIR) techniques, yielding the maximum absolute sensitivity (S_a) and relative sensitivity (S_r) values of 0.642%/K and 0.447%/K at 423 K, respectively. Furthermore, LTWF can be recycled in an aqueous solution and degraded by microorganisms in natural soil into plant nutrients, participating in the carbon cycle with closed-loop characteristics. Consequently, the LTWF with integrated features presents a significant advance in smart agriculture with plant growth lighting and optical thermal sensors.