A self-sacrificial template and a hydrothermal method were utilized to successfully synthesize Ti₃C₂T_x MXene-supported Co₃O₄/Al₂O₃ assembled with nanosheets derived from layered double hydroxides. Within three-dimensional Co₃O₄/Al₂O₃@Ti₃C₂T_x MXene composite, Co₃O₄, as the active center component, was evenly distributed on Ti₃C₂T_x MXene nanosheets and Al₂O₃ as the addition. The 3D structure could expose more active center sites on the surface of Co₃O₄/Al₂O₃@Ti₃C₂T_x MXene and provide more gas diffusion channels, which were beneficial to the gas sensing performance. Comparing to CoAl-LDH@Ti₃C₂T_x MXene (CAM, and CoAl-LDH represents the cobalt-aluminum layered double hydroxide), Co₃O₄/Al₂O₃@Ti₃C₂T_x MXene (CAM-AC) exhibited an enhancing response (S = R₀/R_g = 40.3) and a shorter response time of 1.3 s to 100 ppm NO_x. Besides, CAM-AC also showed an ultra-low detection limit of 10 ppb and excellent repeatability, selectivity and long-term stability. The outstanding gas sensing performance could be attributed to the 3D structure, porous structure and the heterostructure between Co₃O₄/Al₂O₃ and Ti₃C₂T_x MXene. Therefore, the Co₃O₄/Al₂O₃@Ti₃C₂T_x MXene is an excellent NO_x gas sensor candidate.

采用自牺牲模板和水热法成功合成了Ti ₃ C ₂ T _x MXene 负载的Co ₃ O ₄ /Al ₂ O ₃，并由层状双氢氧化物衍生的纳米片组装而成。在三维 Co ₃ O ₄ /Al ₂ O ₃ @Ti ₃ C ₂ T _x MXene 复合材料中，Co ₃ O ₄作为活性中心成分均匀分布在 Ti ₃ C ₂ T _x上MXene 纳米片和 Al ₂ O ₃作为添加物。_{3D结构可以在Co 3} O ₄ /Al ₂ O ₃ @Ti ₃ C ₂ T _x MXene表面暴露出更多的活性中心位点，并提供更多的气体扩散通道，有利于气体传感性能。与 CoAl-LDH@Ti ₃ C ₂ T _x MXene（CAM，CoAl-LDH 代表钴铝层状双氢氧化物）相比，Co ₃ O ₄ /Al ₂ O ₃ @Ti ₃ C ₂ T_{x MXene (CAM-AC) 对 100 ppm NO x}表现出增强的响应 (S = R ₀ /R _g = 40.3) 和 1.3 s 的更短响应时间。此外，CAM-AC 还表现出 10 ppb 的超低检测限以及出色的重复性、选择性和长期稳定性。_{Co 3} O ₄ /Al ₂ O ₃和 Ti ₃ C ₂ T _x MXene之间的 3D 结构、多孔结构和异质结构具有出色的气敏性能因此，Co ₃ O ₄ /Al ₂ O ₃ @Ti ₃C ₂ T _x MXene 是优秀的 NO _x气体传感器候选者。