Tunable properties of carbonitride Ti3C2-yNyTx MXene with varying N contents

Ti₃C_2-yN_yT_x is a two-dimensional (2D) titanium carbonitride in the MXene family, and exhibits tunable physicochemical properties via varying N content. So far, most studies have focused on the synthesis and properties of Ti₃CNT_x (y = 1), while the impact of N/C ratio on the properties of Ti₃C_2-yN_yT_x has not been previously reported, possibly due to the difficult preparation of Ti₃AlC_2-yN_y precursors. In the present study, high-quality Ti₃AlC_2-yN_y MAX precursors were achieved, and the corresponding 2D Ti₃C_2-yN_yT_x MXene flakes were obtained through the HF-etching method. Systematic analysis revealed that varying N content modulates lattice parameters, electrical conductivity, magnetism, and electromagnetic wave (EMW) absorption. Notably, N introduction induces them with room-temperature magnetism, and the synergy of magnetic and dielectric losses enables outstanding EMW absorption across S-, C-, X-, and Ku-bands. This study provides new insights into the controllable synthesis and electromagnetic property regulation of carbonitride MXenes, highlighting their great potential in EMW absorption applications.