Sb(x)‐Doped p‐SnSe (x = 0, 0.05, 0.10, 0.15, 0.20): Bandgap Modulation and Its Impact on Photodegradation of Methyl Orange Dye and Antimicrobial Activity

ABSTRACT Sb‐doped p‐type tin selenide (SnSe) chalcogenides with different Sb concentrations (x = 0.00, 0.05, 0.10, 0.15, and 0.20) were successfully synthesized using the direct vapor transport method in our earlier work, and their optical, morphological, and structural characteristics were carefully described. Building on these discoveries, the current work conducts additional research to assess their antibacterial and photocatalytic uses. While doping‐induced peak shifts and the orthorhombic phase, as proven by X‐ray diffraction (XRD), showed the successful integration of Sb, UV‐visible spectroscopy had previously shown bandgap tunability (1.18–1.46 eV), which improved absorption of visible light. When Methyl Orange dye degradation was used to test the photocatalytic performance under visible light irradiation, Sb 0 . 20 Sn 0 . 80 Se had the greatest degradation efficiency of 94% in 240 min. Higher Sb doping concentrations improved zones of inhibition, demonstrating notable efficiency against Gram‐positive Bacillus subtilis but little activity against Gram‐negative Escherichia coli , according to an evaluation of antibacterial activity. These findings prove that Sb‐doped SnSe is a bifunctional material with potential applications in microbial control and environmental cleanup driven by visible light. Additionally, the work highlights the wider implications of alloy‐engineered SnSe chalcogenides, which are in line with Sustainable Development Goals (SDGs) such as SDGs 3, 6, 12, 13, and 9.