Constructing Quantum Dots/Nano TiO2/ASC Composites as Tiny Electrodes with Efficient Electrocatalytic Property of Rhodamine B

Treatment of various dye wastewaters is of great significance, and semicoke (SC), as a promising electrode material, has attracted much attention from researchers and scholars. Here, we report using SC-based composites for electrocatalytic water oxidation of Rhodamine B (RhB). Carbon quantum dots (CQDs) prepared from SC, Ti3C2Tx quantum dots (Ti3C2Tx QDs), and nano TiO2 were supported on the activated SC (ASC) surface to prepare a series of composites. An UV–Vis detection confirmed the RhB removal rate. The results show that the composites, which act as tiny electrodes with a high mass-transfer rate, exhibited excellent electrocatalytic performance for RhB degradation following pseudo-first-order kinetics. 3% Ti3C2Tx QDs/3% CQDs/8% nano TiO2/ASC composite demonstrated the best catalytic performance, and the RhB removal rate could reach 99.84% at 60 min. Quantum dots (QDs) contributed more than nano TiO2, and CQDs promoted electrocatalytic reactions to a greater extent than Ti3C2Tx QDs. Moreover, the powerful oxidant •OH played a principal role in degrading RhB.