Synergetic Effect of Carbon Dot at Cellulose Nanofiber for Sustainable Metal-free Photocatalyst

Abstract

Metal-free photocatalyst was synthesized by attaching carbon dot (CD) to cellulose nanofiber (CNF) via simple in-situ synthesis. The graphitic core and functional groups of CD on CNF was controlled along the precursor concentration, while the fibrous structure of CNF was intact. The optical property of the samples was profoundly analyzed focusing on the electron recombination pathway. It reveals that the excited electrons in the CD transferred to the CNF and delayed the radiative recombination. The electron-hole pairs were efficiently separated in the composite where abundant amide group and sulfide bonding existed. The CD on the CNF surface improved the morphological stability of CNF under UV irradiation as well. As a result, the composite showed superior photocatalytic performance to degrade 98% of MB molecules within 25 min. The aerogel synthesized from CDCNF had good re-usability without sacrificing its photocatalytic effect. The synthesized CDCNF composite showed superior possibility for applying cellulose nanofiber to sustainable metal-free photocatalyst.