Since 2019, research into MXene derivatives has seen a dramatic rise; further progress requires a rational design for specific functionality. Herein, through a molecular design by selecting suitable functional groups in the MXene coating, we have implemented the dual N doping of the derivatives, nitrogen-doped TiO₂@nitrogen-doped carbon nanosheets (N-TiO₂@NC), to strike a balance between the active anatase TiO₂ at low temperatures, and carbon activation at high temperatures. The NH₃ reduction environment generated at 400 °C as evidenced by the in situ pyrolysis SVUV-PIMS process is crucial for concurrent phase engineering. With both electrical conductivity and surface Na⁺ availability, the N-TiO₂@NC achieves higher interface capacitive-like sodium storage with long-term stability. More than 100 mAh g⁻¹ is achieved at 2 A g⁻¹ after 5000 cycles. The proposed design may be extended to other MXenes and solidify the growing family of MXene derivatives for energy storage.

Metal–organic frameworks (MOFs), a well-known coordination network involving potential voids, have attracted attention for energy conversion and storage. As far as is known, MOFs are not only believed to be crystalline. Emerging amorphous MOFs (aMOFs) are starting as supplementary to crystalline MOF (cMOF) in various electrochemical energy fields owing to intrinsic superiorities over crystalline states, greater ease of processing, and distinct physical and chemical properties. aMOFs retain the basic skeletons and connectivity of building units but without any long-range order. Such structural features over long range possess the isotropy without grain boundaries, resulting in fast ions flux and uniform distribution. Simultaneously, distinct short-range characteristics provide diverse pore confined environment and abundant active sites, and thus accelerate mass transport and charge transfer during electrochemical reactions. Deep understandings and controllable design of aMOF may broaden the opportunities for both scientific researches beyond crystalline materials and practical applications. To date, comprehensive reviews about aMOFs in the fields of energy conversion and storage remain woefully underrepresented. Herein, we summarize the roadmap of aMOF from the development, structural design, opportunity, application, bottleneck, and perspective. In-depth structure–activity relationships with aMOF chemistry are highlighted in the typical electrochemical energy conversion like water oxidation and energy storage, including supercapacitor and battery. The combination of disordered nature at long range and short range, alongside the dynamic structural changes, is promising to reinforce cognition of aMOF domains with MOF versatility, shedding light on the design for efficient electrochemical energy applications via amorphization.