Unveiling quaternary GeSbSeEr chalcogenides as photocatalyst: Degradation of cationic and anionic pollutant in visible light

Abstract

This article presents the photo-catalytic dye-degradation from pure and doped multi-component Ge17Sb8Se75-xErx(x = 0, 0.2, 0.4, 0.6, 0.8, 1) chalcogenides system has been established in visible light (orange ∼590 nm) for the first time. Band-gap shifting, suitable band position and higher absorption of visible range radiation have been accounted for Er doping to realize the improvement in electron-hole pair production. The improvement in the photo-catalytic activity dye degradation efficiency of 89% in 90 min for methylene blue and 76% for methyl orange has been achieved for certain compositions of chalcogenides glass which were synthesized by traditional melt quench approach. Further, SEM-EDX Photoluminescence and Raman spectroscopy measurements of these samples are supplemented to deliberate the composition, band edge transitions and chemical signatures of Ge17Sb8Se75-xErx. Overall, the presence of Er ions as well as the band to band transition (∼664 nm) in the chalcogenides system is found to play a decisive role in the photo catalytically process involved for competitive dye degradation to replace conventional dyes working in the UV range.