Ambient air annealed Sb2S3 thin films and enhanced photocatalytic performance via Sb2S3/ZnO heterostructure fabrication

This work examines the effect of annealing temperature on Sb 2 S 3 thin films in ambient air, aiming to enhance their potential as a photocatalyst in a bilayer heterostructure. The structural, morphological, optical, and electrical properties were studied using XRD, Raman spectroscopy, UV.Vis, AFM, and photoresponse measurements. Structural analysis confirmed the formation of a pure stibinite phase at 300 °C and 350 °C. The films annealed at 300 o C and 350 o C showed band gap values of approximately 1.69 eV, close to that reported for Sb 2 S 3 . The films annealed at 350 °C showed the highest photosensitivity. ZnO, Sb 2 S 3 and Sb 2 S 3 /ZnO films were evaluated for their photodegradation performance at controlled laboratory conditions under UV-visible irradiation. The Sb 2 S 3 /ZnO heterostructure showed the highest degradation percentages of 100 % in 165 minutes compared to 68 % for ZnO alone. Additionally, kinetic analysis revealed a significantly higher rate constant (2.06 × 10 -2 min -1 ) and a shorter half-life (33.59 min) for the Sb 2 S 3 /ZnO heterostructure compared to pure ZnO (7.34 × 10 -3 min -1 , 94.43 min), confirming its superior photocatalytic efficiency. • Sb 2 S 3 /ZnO heterojunctions for photocatalytic applications via Chemical Bath Deposition • Recrystallization of Sb 2 S 3 without inert or vacuum environments • Enhancement of photocatalytic activity from heterojunction formation, ∼ 68 % for pure ZnO to ∼100 % for Sb 2 S 3 /ZnO in 165 min. • Proposed charge transport mechanism leading to the improved photocatalytic efficiency