Ternary MXene/MnO2/Ni composites for excellent electromagnetic absorption with tunable effective absorption bandwidth

Ni Doping in MnO2/MXene (Ti3C2Tx) Composites to Modulate the Oxygen Vacancies for Boosting Microwave Absorption

“…The diameter of MnO 2 nanorods is 30–50 nm. In particular, the random distribution of MnO 2 could provide more transmission paths for electromagnetic waves, which is expected to be conducive to enhance the microwave absorption performance Figure d,e indicates the high-resolution TEM (HRTEM) images of the Ni–Mn/MX-2 composites, where the coexistence of the MnO 2 and Ti 3 C 2 T x phase can be clearly observed.…”

“…In particular, the random distribution of MnO 2 could provide more transmission paths for electromagnetic waves, which is expected to be conducive to enhance the microwave absorption performance. 18 32,33 The investigation of the XPS spectra of Ni 2p demonstrates the coexistence of Ni 2+ and Ni 3+ in the composite, which inevitably causes a jump in the electronic valence state, leading to Debye relaxation during electro-magnetic attenuation. 33 Therefore, it is advantageous to achieve enhanced microwave absorbing properties depending on Ni doping.…”

“…It has been intensively studied due to its low cost of preparation as well as its abundant natural resources, environmental compatibility, and unique physical and chemical properties. 15 So far, electromagnetic microwave absorption of MnO 2 nanostructures in the form of nanoparticles, 16 nanosheets, 17 and nanorods 18 have been reported. Nickel is widely used as a dopant to improve the electronic structures and electromagnetic properties of MnO 2 .…”

“…A previous study has found that the incorporation of MnO 2 nanorods can tune the dielectric performance of Ti 3 C 2 T x MXene to show controllable microwave absorption. 18 It is greatly hoped that combining MXene with MnO 2 nanorods to modify the electronic structure in the form of Ni doping, that is Ni−MnO 2 /MXene composites, will realize excellent electromagnetic wave absorption. Moreover, the fundamental mechanism could be revealed in depth to facilitate the studies of the influence of defects on microwave absorption.…”

“…Additionally, Ni doping could induce a valence state change in the material, which is likely to induce a large number of vacancy defects to balance the valence state. − It is worth mentioning that oxygen vacancies are closely related to the microwave absorption characteristics in terms of improving electrical conductivity and enhancing polarization relaxation. , Compared with the MnO 2 particles and nanosheets, MnO 2 nanorods are conducive to construct a three-dimensional conductive network, thereby enhancing the conductance loss. A previous study has found that the incorporation of MnO 2 nanorods can tune the dielectric performance of Ti 3 C 2 T x MXene to show controllable microwave absorption . It is greatly hoped that combining MXene with MnO 2 nanorods to modify the electronic structure in the form of Ni doping, that is Ni–MnO 2 /MXene composites, will realize excellent electromagnetic wave absorption.…”