Interfacial charge transfer in LaCoO3/SnS2 heterostructure for boosted photodegradation of environmental organic pollutant

Abstract

Herein, we report an efficient multicomponent photocatalytic system prepared via ultrasonication of LaCoO₃ and SnS₂ in different weight percentages (X% = 2.5, 5, 7.5 10 and 12.5 % SnS₂) and employed for photodegradation of Alizarin Red S (ARS) and Rhodamine B (RhB) dyes. The synthesized catalysts were subjected to structural, optical, morphological, and electrochemical characterizations. The X-Ray diffraction patterns of LSn-X% (when, X ≤ 12.5 %) were indexed to rhombohedral LaCoO₃ without having any diffraction patterns of SnS₂. However, morphological studies and elemental analysis show the presence of fine dispersion of SnS₂ within the LSn-X% heterostructure. Detailed photocatalytic investigation portrays superior performance of LSn-10 % with a rate constant of 4.9 × 10^–2 min^-1 and 3.2 × 10^-2 min^-1 against ARS and RhB dyes, respectively. Further, the observations from optical and electrochemical studies help to figure out why LSn-10 % offered the best photocatalytic performance among the synthesized catalysts. Radical reveals that the superoxide and hydroxide radicals were found to be the key radicals responsible for photocatalytic degradation of ARS and RhB dyes were The CB and VB potential of LaCoO₃ is found to be 1.25 and -0.99 eV; for SnS₂ it is found to be 1.95 and 0.045 eV. Finally, considering all these observations a possible degradation mechanism was proposed. Overall, highly efficient visible light active photocatalysts were explored which may open the possibility of utilizing the photocatalyst for real-time degradation of environmental pollutants.