Visible-light-induced enhanced photocatalytic degradation of Rhodamine-B dye using BixSb2-xS3 solid-solution photocatalysts

Abstract

The present work examines binary solid solutions of BixSb2-xS3 [x = 0.536, 1.09, 1.68] toward photocatalytic degradation of Rhodamine-B (RhB) under visible light. Phase and microstructural analysis confirmed the formation of Bi0.536Sb1.464S3, Bi1.09Sb0.91S3, and Bi1.68Sb0.32S3 solid-solution phase with nanorods (~25–50 nm average diameter) morphology. The synthesized products show outstanding photocatalytic degradation of RhB with ~95–99.5% degradation achieved within 30 min. The kinetic study finds the high degradation efficiency (~98%) of BixSb2-xS3 photocatalysts stems from the amenable band gap (~2.3 eV, confirmed from DRS study), and higher separation efficiency of photogenerated electron-hole pairs (established from PL studies). The complete detoxification of RhB dye was confirmed by quantitative estimation of CO2 post photodegradation through GC analysis. Moreover, due to the solid and hard nature of the photocatalysts, it was easily recovered from the reaction mixture and reused multiple times without losing the degradation behavior. The parallel comparison with other active photocatalysts demonstrates BixSb2-xS3 [x = 0.536, 1.09, 1.68] have higher catalytic efficiency with similar dosing hitherto reported in the literature and possibly can be used for degradation of other organic dyes using the visible spectrum.