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

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 [email protected]2 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 [email protected]2 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.