CQD/TiO2 nanocomposite photocatalyst for efficient visible light-driven purification of wastewater containing methyl orange dye

In this study, we report a cost effective and facile synthesis method for preparing carbon quantum dot incorporated TiO2 nanocomposite (CQD/TiO2) for rapid photodegradation of methyl orange (MO) under direct and indirect sun irradiations. In practice, TiO2 nanosols and CQD were prepared by sol-gel and hydrothermal routes, subsequently their nanocomposites (CQD/TiO2) by sonication assisted mixing process at ambient conditions. Different analyses like XRD, FTIR and SEM/EDX. TEM, XPS, Zeta-potential were employed to characterize the prepared catalysts. CQD/TiO2 prepared in the weight ratio of 1:10 of CQD and TiO2 exhibited optimized MO-photodegradation (three folded to the activity of pure TiO2) in direct sunlight exposures at pH 11. The results show that variations in the initial concentration and pH of MO solution as well as catalyst loadings have a significant impact on the photocatalytic performance of CQD/TiO2. Similar MO-percentage degradations for five consecutive cycles highlighted its long-term catalytic stability and good reusability potential. Because of good visible-light photocatalytic efficiency, profound catalytic-stability, and reusability for dyes photocatalysis, CQD/TiO2 nanohybrid is a potential candidate for photocatalytic purification of textile and other organic based wastewater under direct and indirect solar light exposures.

Automated summary

This study reports a cost-effective and facile synthesis method for preparing carbon quantum dot incorporated TiO2 nanocomposite for rapid photodegradation of dyes under direct and indirect sun irradiations. The prepared CQD/TiO2 exhibited good photocatalytic performance, catalytic stability, and reusability potential.