Eco‐Friendly Synthesis of MXene Nanoflakes from Agricultural Waste and the Influence of Flake Size and Layer Number on Antibacterial, Photothermal, and EMI Shielding Performance of Functional Textiles

MXene nanoflakes are synthesized from carbon sources derived from low‐cost agricultural waste‐based activated carbon (LAC) and high‐cost titanium carbide (HTiC). The results show that the low‐cost, environmentally friendly MXene‐LAC has thinner flakes, fewer layers, and larger flake sizes compared to MXene‐HTiC, which led to a greater monolayer‐like structure and higher electrical conductivity. Given the linear correlation between electrical conductivity and the photothermal, antibacterial, and electromagnetic interference (EMI) shielding properties of the coated fabrics, it can be concluded that the low‐cost MXene‐coated fabric (PET‐MX‐LAC) exhibits higher electrical conductivity, better photothermal conversion (80.7 ± 0.3 °C), and outstanding antibacterial performance both in dark conditions and under light exposure. It shows 95.18% ± 1.62% antibacterial efficiency against the Gram‐positive Staphylococcus aureus and 99.99 ± 0.3% activity against the Gram‐negative Escherichia coli . Furthermore, the overall EMI shielding effectiveness for PET‐MX‐LAC fabric is 34.64 ± 0.81 dB for a single layer and 42.65 ± 0.74 dB for a double layer. Therefore, by producing low‐cost and eco‐friendly MX‐LAC MXene with larger flakes and fewer layers, and coating it onto polyester fabric, it is possible to produce low‐cost multifunctional textiles with excellent photothermal antibacterial and EMI shielding properties, high stability, and the preservation of the inherent properties of the fabric as much as possible.