Utilizing conventional wood preservatives poses potential risks to ecosystems and human health. Therefore, the wood protection industry must develop alternatives that are both efficient and environmentally friendly. In this paper, industrial tobacco waste extracts were used as eco-friendly wood preservatives against wood decay fungi. Three major constituents in the extracts were identified via gas chromatography-mass spectrometry (GC-MS) and included nicotine, neophytadiene, and 2,7,11-cembratriene-4,6-diol. The antifungal activities of waste tobacco extracts and these three major constituents against wood decay fungi were tested. At a concentration of 40 mg/mL, the tobacco waste extract treated with 50% ethanol significantly inhibited the activity of wood decay fungi. This was because the extract contained nicotine as the primary active component and neophytadiene as a synergistic active component. Wood decay resistance tests were conducted on Pinus yunnanensis and Hevea brasiliensis treated with a 50% ethanol extract of tobacco waste at a concentration of 40 mg/mL. The mass losses of Pinus yunnanensis exposed to G. trabeum and T. versicolor were 4.11% and 5.03%, respectively, while the mass losses in Hevea brasiliensis exposed to G. trabeum and T. versicolor were 7.85% and 9.85%, respectively, which were classified as highly resistant. The acute ecotoxicity of the tobacco waste extract was assessed using a kinetic luminescent bacteria test with Aliivibrio fischeri, which revealed significantly lower acute toxicity than a commercial copper-based wood preservative. This study offers insights into high-value utilization of tobacco waste and advancement of natural wood preservatives.

Lightweight structural materials that combine high strength, machinability, and sustainability are essential for next-generation construction. Wood, a renewable and low-carbon resource, offers excellent mechanical performance but remains limited by fastener stability and reliance on metals and adhesives. Here, we report a superstrong engineered wood produced through synergistic cell-wall engineering across cellular and molecular scales, enabling metal-free and adhesive-free cross-laminated timber. Pressure-controlled densification induces near-complete closure of open cells in natural beech wood, generating a dense, smooth architecture with a 3-dimensional mechanical interlocking network analogous to micro-mortise-and-tenon joints. The resulting material preserves the intrinsic anisotropic architecture of wood while forming a 3-dimensional mechanical interlocking network resembling micro-mortise-and-tenon joints. Wooden structural material exhibits substantially improved dimensional stability and mechanical performance, including a density of 1.33 g cm ⁻³ , a flexural strength of 150.89 MPa, a compressive strength of 88.48 MPa, and an exceptional Janka hardness of 18.84 kN. Wood-derived nails fabricated from this material function comparably to steel fasteners, providing high strength-to-weight ratios while eliminating corrosion and adhesive contamination. This approach advances timber construction toward higher performance, reduced environmental impact, and improved sustainability, offering a scalable pathway for green building applications.