Achieving excellent microwave absorption performance in ultralight Ti3C2Tx MXene with M−O bonds (M = Fe, Co, Ni) as surface terminating groups

Modulating surface terminating groups has been recognized as an effective approach for regulating the electrical properties of MXene. Nevertheless, achieving the simultaneous majorization of electrical and magnetic properties of MXene through terminating groups modulation remains an essential challenge. Herein, we present an innovative series of M−Ti₃C₂T_x (M = Fe, Co, Ni) with M−O bonds as partial terminating groups. First principles calculations are employed to investigate the impact of M−O bonds on electrical properties of M−Ti₃C₂T_x. The M−O bonds introduce magnetic loss mechanisms while increasing polarization relaxation and conductivity, resulting in a synergistic optimization of dielectric and magnetic loss. Consequently, the Fe–Ti₃C₂T_x achieves a favorable minimum reflection loss (RL_min) of − 53.01 dB at 2.47 mm and an effective absorption bandwidth (EAB) of 4.20 GHz at 1.34 mm. The RL_min of Co–Ti₃C₂T_x reaches − 54.90 dB at 1.43 mm with an EAB of 3.94 GHz at 1.35 mm. The Ni–Ti₃C₂T_x attains a RL_min of − 47.66 dB and a remarkable EAB of 4.90 GHz at 1.58 mm and 1.63 mm, respectively. Notably, these excellent MA performances are accomplished with an exceptionally low filling ratio of merely 2 wt%, completely satisfying lightweight requirements of absorbers. This research presents a novel method for designing efficient absorbers with simultaneous optimized electromagnetic properties by terminating groups modulation.