Superhydrophobic microwave absorption cotton fabrics prepared on the basis of porous flower-like MoS ₂ /bagasse carbon composite materials

Bagasse-based porous carbon (BPC) with low cost, light weight, and sustainability was synthesized from natural waste bagasse through carbonization and activation processes. Porous flower-like MoS 2 /BPC were then successfully fabricated via in-situ formation of flower-like MoS 2 within the porous structure of BPC by hydrothermal method. The flower-like MoS 2 /BPC were combined with the low surface energy substance polydimethylsiloxane (PDMS) to functionalize cotton fabrics via a simple dip-coating method. The effects of MoS 2 /BPC concentration and PDMS concentration on the hydrophobicity of the treated cotton fabrics were systematically investigated. The results demonstrated that when the PDMS concentration is 3% and the flower-like MoS 2 /BPC concentration is 0.2%, the cotton fabrics exhibit the excellent superhydrophobicity with a water contact angle of 158.4°. Additionally, the minimum reflection loss (RL min ) of the coated cotton fabric is -35.19 dB at 10.3 GHz in the frequency range of 8.2-12.4 GHz with effective microwave absorption bandwidth (EAB) of 3.318 GHz. The results suggest that porous flower-like MoS 2 /BPC contribute surface roughness to the cotton fabric, while PDMS imparts low surface energy with excellent bonding properties. The heterogeneous structure of MoS 2 /BPC composites coated onto the fabric can lead to optimized impedance matching, thereby achieving conductive loss, polarization relaxation, and multiple reflection loss. Consequently, the resulting cotton fabric demonstrated exceptional properties, including effective microwave absorption, self-cleaning ability, as well as waterproof and stain-resistant characteristics. This study provides a feasible approach for the development of novel biomass-derived porous carbon materials with strong broadband electromagnetic absorption capabilities.