CVD carbon-coated carbonized loofah sponge loaded with a directionally arrayed MXene aerogel for electromagnetic interference shielding

Abstract

Sustainably regenerated, environmentally friendly, natural loofah sponge is promising to become a multi-functional bio-carbon material, especially in the field of electromagnetic shielding, due to its unique hierarchical structure. In this work, highly efficient electromagnetic shielding composites were obtained based on CVD carbon-coated carbonized loofah sponge (CCLS) and directionally arrayed MXene aerogels through a simple and pollution-free freeze-drying method. The three-dimensional skeleton of CCLS was able to provide a mechanically strong support for the MXene aerogel and endow the composites with a good foundation network for electric conduction and shielding electromagnetic waves. When the CVD carbon coating time was 60 hours, the compressive strength and modulus of CCLS reached 0.979 MPa and 10.881 MPa, respectively, and an electrical conductivity of 28.34 S m⁻¹ was attained. In particular, the directionally arrayed MXene aerogel with a microporous structure filled the macropore vacancies in the CCLS skeleton, giving the composite prominent anisotropy. The maximum conductivity and average total electromagnetic shielding effectiveness of the composites prepared achieved levels of 55.99 S m⁻¹ and 70.0 dB, respectively. Importantly, the composite showed excellent flame resistance and thermal stability. The electromagnetic shielding effectiveness value of the composites could still reach 42.6 dB after being burnt in an alcohol flame for 120 s. This research could further widen the practical application and development of natural biological materials and aerogels in various fields such as aerospace, medical equipment, electronic devices, and energy management.