Ti–N–C Bonded Close-Coupled TiO2/g-C3N4 for Rapid Degradation of Cationic Dyes from a Multi-Dye System by Persulfate Activation

Abstract

A novel Z-Scheme photocatalyst (TCN) was prepared with TiO2 and graphitic carbon nitride (GCN) and utilized to study the degradation efficiency of a binary dye mixture consisting of 5 ppm Rhodamine B (RhB) and 5 ppm Crystal Violet (CV) solutions by persulfate activation. Derivative spectrometric analysis was adopted to find the degradation efficiencies of the individual dyes in the mixture. The results indicate that in the presence of persulfate ions 0.6 TCN gives 100 % degradation in 60 min and 30 min for Rh B and CV, respectively. Hydroxyl radicals, superoxide radicals, and sulfate radicals were found to be the active species involved in photocatalytic degradation. From the results of radical scavenging experiments and band potentials of the semiconductors, a plausible mechanism of photocatalytic degradation of the model pollutants is proposed.