TEMPO oxidized nanofiber carbon quantum dots/TiO2 composites with enhanced photocatalytic activity for degradation of methylene blue

• CQDs/TiO 2 were prepared via a facile and time-saving one-pot method. • CQDs/TiO 2 composites exhibited high photocatalytic degradation efficiency up to 92%. • The abundant groups on CQDs can improve the photophysical property of the catalyst. • Bio-based cellulose is helpful for reusing and reducing the cost of the catalyst. Carbon quantum dots/titanium dioxide (CQDs/TiO 2 ) nanocomposites were synthesized with TEMPO oxidized cellulose as carbon source via a facile method. In this eco-friendly system, the photocatalytic activity of CQDs/TiO 2 were evaluated through photo-degradation of methylene blue (MB) under visible light. The results show that CQDs/TiO 2 composites possess high photocatalytic degradation efficiency up to 92%. The enhanced degradation efficiency of MB was probably attributed to that the photoelectrical properties of CQDs can lead to effective separation of photo-generated electrons-holes pairs. Moreover, the TEMPO oxidized cellulose has abundant amino groups, which can significantly improve the photophysical properties of CQDs.