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 Ndoped 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 sodiumion batteries, the CQDs@TiO₂ product annealed at 500℃ 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.