Enhancing photodecomposition of cationic organic dyes of rhodamine and methylene blue employing the Ta2O5-CdS composite driven by visible light irradiation

The Ta2O5-CdS composites with the various ratios of Ta2O5/CdS were synthesized to study their employment in the photodecomposition of RhB (rhodamine B)/MB (methylene blue). The samples characterized by XRD, FESEM, EDS, and TEM proved the formation of the Ta2O5-CdS with cauliflower morphology. According to DRS analysis, Ta2O5-CdS exhibited redshifts, and their band-gaps (2.00 eV and 2.10 eV for Ta2O5/CdS = 1 and 3) decreased in contrast to pure CdS (2.18 eV). The BET-specific surface areas (9.221 m2/g) of the Ta2O5-CdS composite (Ta2O5/CdS = 1) measured by N2 adsorption-desorption isotherms were enhanced in contrast to pure CdS (1.817 m2/g). Moreover, MB photodecomposition by Ta2O5-CdS with the weight ratios of Ta2O5/CdS = 3 and 1 improved to 90% and 99%, respectively, in contrast to pure CdS (80%). Besides, the Ta2O5-CdS composite (Ta2O5/CdS = 1) exhibited the highest RhB decomposition (97%). Hence, for the first time, this study has surveyed the photodecomposition of the cationic dyes by the Ta2O5-CdS with excellent photocatalytic perfor-mance. The role of active species was detected through species quenching tests. A reliable mechanism was suggested to reveal how the RhB/MB decomposition was promoted compared to CdS. The photodecomposition results corresponded to the pseudo first order kinetic model.

Automated summary

The Ta2O5-CdS composites with different ratios of Ta2O5/CdS were synthesized and their application in the photodecomposition of RhB/MB was studied. The results showed that Ta2O5-CdS had a cauliflower morphology characterized by XRD, FESEM, EDS, and TEM. DRS analysis indicated a redshift and a decrease in band-gaps for Ta2O5-CdS compared to pure CdS. The BET-specific surface areas of Ta2O5-CdS were higher than pure CdS. Additionally, the Ta2O5-CdS composites demonstrated improved photodecomposition of RhB/MB compared to pure CdS.