Investigation on the structural quality dependent electromagnetic interference shielding performance of few-layer and lamellar Nb2CTx MXene nanostructures

Tunable Electromagnetic Interference (EMI) shielding behaviors of 2D MXene (Nb2CTx) were explored via different exfoliation conditions. Stacked, lamellar few-layer, oxygen-related surface functional groups, and structural defects along with oxidative products of Nb2CTx were identified by tuning chemical etching conditions during one-step exfoliation process. Exfoliation of Nb2CTx with a tightly packed stacked structure remarked at lower etching times. The unpacking of Nb2CTx into lamellar morphology followed by separated few-layer Nb2CTx remarked at moderate etching time, whereas structural misalignment, defects, and oxidation of Nb2CTx occurred during prolonged chemical etching times. Synergistic effect of one-step extracted few-layers and lamellar structured Nb2CTx favorably enrich the assembly of multiple electrical conductive pathways responsible for absorption dominated EMI shielding performance in X- and Ku-band region. The assembled wax nanocomposites with 80% of Nb2CTx loading exfoliated at 100 h etching time at a thickness of 1 mm exhibited EMI shielding effectiveness of about 44.09 ± 1.99 dB at 12 GHz, and its EMI attenuation mechanism explained by conduction and eddy current loss. The combined action of few-layer and lamellar Nb2CTx nanostructures could be interesting for making novel shielding materials; open a new avenue for niobium series in the MXene family for elaborated applications.