Boosting sodium storage of mesoporous TiO2 nanostructure regulated by carbon quantum dots

N-doped TiO2 mesoporous nanostructure has been synthesized via a facile CQDs-regulated hydrothermal route. The resulting TiO2 product shows the large surface area, high conductivity, abundant mesopores, and excellent sodium storage capability. [Display omitted] It has been demonstrated that the conductivity and electrochemical properties of TiO2 nanomaterials can be significantly improved by an incorporation of carbon additives. In the study, we develop a novel N-doped TiO2 mesoporous nanostructure via the addition of carbon quantum dots (CQDs) solution following a scalable hydrothermal process. The as-made TiO2 product shows well-defined morphology, high conductivity, large surface area, and abundant mesopores. When evaluated as anodes for sodium-ion batteries, the CQDs@TiO2 product annealed at 500 °C exhibits a superior sodium storage capability. It delivers a high reversible capacity of 168.8 mAh/g at 100 mA/g over 500 cycles and long cycling stability. The remarkable performance of CQDs@TiO2 mainly arises from the large surface area and mesoporous architecture constructed by ultrathin TiO2 nanosheets, as well as the full cooperation between CQDs and TiO2.