The design of lignin nanostructures, which leverages interfacial interactions to enhance colloidal network entanglement, holds promise for expanding their applications in polyvinyl alcohol (PVA) composites. Herein, a novel approach is proposed for fabricating lignin nanobottles (LNBs) using biomass-derived γ-butyrolactone (GBL) to create hollow interiors connected to a single surface opening. The resulting LNBs exhibit uniform sizes of approximately 108 nm with an opening diameter of 34.94 nm. Incorporating LNBs into PVA composites enhances mechanical properties significantly, with a tensile strength of 64.96 MPa and an elongation at break of 611.6 %. Moreover, the nanocomposite films demonstrate notable antibacterial effects, UV protection, and hydrophobicity. Introducing LNBs improves photothermal conversion capacity, achieving a temperature of 62.1 °C in just 150 s. Furthermore, a meticulously designed 3D solar evaporator demonstrates remarkable evaporation performance, achieving a rate of up to 1.89 kg m-2h−1 with an outstanding efficiency of 96.55 %. When exposed to 1 sunlight, the thermoelectric material generates an output voltage of 0.83 V, indicating considerable potential for energy generation. Overall, Incorporating LNBs enhances lignin’s effectiveness in materials and provides a novel approach to augment lignin’s photothermal properties, enabling broader applications in solar-driven evaporation and thermoelectric materials.