Controlled synthesis and superior UV-visible photocatalytic activity of carbon quantum dots encapsulated with silica

Abstract

• Synthesis of C-QDs was performed from dehydration of Glucose-D in concentrated sulphuric acid at room temperature. • Silica encapsulated C-QDs were carried out in situ, followed by high temperature calcination. In this work, we report a facile one-step approach to prepare carbon quantum dots doped silica. Carbon quantum dots (C-QDs) were synthesized using Glucose as precursor and sulfuric acid (98%) as carbonating agent in aqueous medium. The encapsulation of C-QCDs was then achieved by in situ hydrolysis of precursor Tetraethyl orthosilicate (TEOS) through Solgel method. The structural studies of C-QDs doped silica was done by powdered X-ray diffraction ( p -XRD). The optical characterization of the prepared C-QDs was performed by Ultraviolet-visible (UV-vis) spectroscopy. Consequently, the as-prepared C-QCDs were found to be highly fluorescent with little crystallinity. The morphological investigation of as-made silica and C-QCDs doped silica was studied by field emission scanning electron (FSEM). In order to study photodegradation studies methylene blue was used as model compound. C-QCDs doped silica showed higher degradation (98.5%) in comparison to the pristine C-QDs (38%) and silica (76%) in neutral media.