A Novel Approach for P25‐Carbon Dot Composite and the Reactive Oxygen Species Involved in the Visible Light Photocatalytic Mineralization of Rhodamine B

Abstract

A novel approach has been adapted for making titanium dioxide (P25)‐carbon dot composite (P25/C‐dot) and it exhibits visible light (VL) photocatalytic mineralization property towards rhodamine B (RhB). Carbonization of β‐cyclodextrin (CD) in a self‐assembled P25/β‐cyclodextrin (P25/CD) composite prepared by UV‐irradiation, using P2O5‐water yields P25/C‐dot with chemical linkage between P25 and C‐dot. Photodegradation (PD) of RhB by P25/CD and P25/C‐dot were better (71%) than that of the commercial P25 (49%). Though the PD activity of both the composites was similar, the PD of RhB by P25/C‐dot follows the mineralization pathway while that in the presence of P25/CD undergoes via decolouration. Further scavenging studies reveal that hydroxyl radicals (•OH) are the dominant reactive oxygen species (ROS) in the PD of RhB by P25/C‐dot while it is superoxide anion radical (O2•−) and singlet oxygen (1O2) for P25/CD, suggesting that •OH can promote mineralization of the RhB. Our study suggests that C‐dot has a role in the formation of •OH during PD reaction, catalytically or not.

Polyaniline-Derived Nitrogen-Doped Graphene Quantum Dots for the Ultratrace Level Electrochemical Detection of Trinitrophenol and the Effective Differentiation of Nitroaromatics: Structure Matters

“…Moreover, the N-doping in the aromatic lattice would result in an N-GQD with defects in the aromatic structure due to N-doping and with lower percent of lattice N-doping due to the stability of aromatic structure. The bottom-up methods had been from biomolecules, such as cyclodextrin, glucose, citric acid, , and so forth, which are aliphatic in nature, in the presence of N-precursors; for example, citric acid in the presence of dicyandiamide, citric acid with urea, , GO in the presence of ammonia, GQD with hydrazine, and strong acid treatment of N-doped graphene …”

Polyindole-Derived Nitrogen-Doped Graphene Quantum Dots-Based Electrochemical Sensor for Dopamine Detection

“…Additionally, this would create many defects in the aromatic structure, and the percentage of N-doping within the lattice will be lower. The bottom-up method includes the synthesis of quantum dots from glucose, cyclodextrin, citric acid, and so forth, in the presence of N-precursors [ 25 , 26 , 27 , 28 , 29 , 30 ]. Indeed, the simplicity in operation and ambient reaction conditions offered by the hydrothermal approach is preferred over the other methods for the formation of N-GQDs with N-rich aromatic domains [ 1 ].…”