Ag anchored mesoporous carbon hollow sphere in Cellulose nanofibers/MXene composite films for high-performance electromagnetic interference shielding

The increasingly serious electromagnetic (EM) radiation and related pollution effects have gradually attracted people's attention in the information age. Hence, it's crucial to develop adaptive shielding materials with minimum EM waves (EMW) reflection. In this paper, Ag nanoparticles loaded mesoporous carbon hollow spheres (MCHS@Ag) were synthesized by chemical reduction method, and cellulose nanofibers (CNF)/MXene/MCHS@Ag homogeneous composites were prepared. The total EM interference shielding efficiency (SE_T) of CNF/MXene/MCHS@Ag composite film was 32.83 ​dB (at 12.4 ​GHz), and the absorption effectiveness (SE_A) was improved to 26.6 ​dB, which was 63.1% and 195.5% higher than that of CNF/MXene/MCHS composite film. The low dielectric property of MCHS effectively optimized the impedance matching between the composites and air. The hollow porous structure prolonged the transmission path of EMW and increased the absorption loss of the composites. At the same time, Ag nanoparticles located the MCHS were helpful to construct the internal conductive path overcoming the damage of the conductive property caused by the low dielectric of MCHS. This research adopts a straightforward method to construct a lightweight, pliable, and mesoporous composites for EMI shielding, which serves a crucial role in the current era of severe EM pollution.