Full-wood photoluminescent and photothermic materials for thermal energy storage

Due to its unique structure and component, wood is widely used as matrix to develop functional composites. However, the lignin is removed from wood and thrown away as waste in most wood-based functional composites. In this work, a new strategy of “taken from the wood, back into the wood” to fabricate a full-wood photoluminescent and photothermic material is proposed. By facile delignification and solvothermal process, the delignified wood (DW) and carbon quantum dots (CQDs) derived from removal lignin are prepared. In addition, compared with other CQDs excited by UV light, the CQDs possess red (650 nm) and NIR (710 nm) emission light under visible light excitation (580 nm). Most importantly, the heat radiated from NIR emission could be stored by the introduced phase change materials (PCM) to adjust ambient temperature. The composite owns photoluminescent, photothermic and energy storage property (heat latent of 137.6 J/g), which is environmentally friendly, green and creative. The all-new technique for functional wood composite shows potential for application in energy-saving and optical devices.