One‐Step In Situ Formation of N‐doped Carbon Nanosheet 3D Porous Networks/TiO₂ Hybrids with Ultrafast Sodium Storage

Abstract In spite of the satisfactory advancement in preparing TiO₂‐based hybrid structures, most methods rely on additional template‐based multistep reactions for engineering the given structure. Herein, a unique self‐template and in situ recrystallization strategy is explored to synthesize uniform flowerlike multicompositional structures of nitrogen‐doped porous carbon nanosheet networks immobilizing TiO₂ nanoparticles (TiO₂∩NPCSs) via a self‐prepared single precursor and subsequent thermal treatment. Depending on the unique coordination ability of 2,4‐dihydroxybenzoic acid with metal ions under alkaline conditions to form a flowerlike network, a self‐produced single precursor can be achieved. Careful investigations of the self‐prepared precursor reveal a high practicability of the present synthetic scheme. Because of the novel structural and compositional features, these TiO₂∩NCSN flowers indicate superior sodium storage properties when evaluated as anodes for sodium‐ion batteries. Impressively, the TiO₂∩NCSN flowers deliver high reversible capacities of 152 mAh g⁻¹ at 2C for 3000 cycles and 114 mAh g⁻¹ at 10C for 10000 cycles, as well as an ultrahigh rate capability up to 50C with a capacity of 101 mAh g⁻¹. The facile method could stimulate further capability in precise construction of complex architectures with complicated compositions for different device applications.