Sustainable, High‐Performance, Aqu‐Recyclable Transparent Panels via Phase Engineering and Water‐Induced Plasticization of Bamboo

The advent of biomass‐origin transparent panels, such as transparent wood, heralds a paradigm shift in the utilization of natural light for energy‐efficient construction and a plethora of optical applications. However, it current relies on fossil‐based polymers for index‐matching, along with a lack of recyclability and constraints in scalable production to larger dimensions. Here, a bottom‐up strategy is proposed for preparing sustainable transparent panels from bamboo powder by reconstructing the hydrogen‐bond network of cellulose into a dynamic covalent structure via sodium periodate oxidation and water‐induced formation of hydrated aldehydes. The resultant all‐biobased transparent panels exhibited both high transmittance (>85%) and haze (>75%), excellent mechanical strength (≈83 MPa tensile strength), and remarkable water resistance. Moreover, this transparent panel exhibits potential for perovskite solar cells integration, enhancing power‐conversion efficiency from 22.57% to 23.33%. Importantly, the end‐of‐life transparent panels can be easily recycled via moisture control, or alternatively repurposed as high‐performance bio‐based adhesives through pulverization and water mixing. This closed‐loop recyclability with low carbon footprint, combined with high strength, efficient power conversion, and aqu‐recyclability, establishes a sustainable pathway for construction and optical applications.