Multi-interfaced SnS₂/ZrO₂/g-C₃N₄ ternary nanocomposites: Charge transfer mechanistic exploration and enhanced photodegradation efficiency towards Rhodamine B dye and ciprofloxacin antibiotic

This study investigates the synthesis and photocatalytic performance of binary ZrO₂/g-C₃N₄ (CZ) and ternary SnS₂/ ZrO₂/g-C₃N₄ (CZS) photocatalysts. The primary objective is to address the need for more effective photocatalysts for organic pollutant degradation. Specifically, the research seeks to understand how varying ZrO₂ and SnS₂ contents influence photocatalytic efficiency. To explore this, g-C₃N₄ was synthesized via thermal polymerization, ZrO₂ via hydrothermal methods, and the binary and ternary composites using precipitation methods. Comprehensive characterization of the photocatalysts was performed using XRD, XPS, UV–Vis DRS, HRTEM, EDX, PL, FESEM, and Zeta potential analysis. The photocatalysts were evaluated for their ability to photodegrade ciprofloxacin (CP) and Rhodamine B (RhB) under visible light exposure. The findings indicate the incorporation of ZrO₂ enhanced the degradation efficiency of g-C₃N₄. The ternary composite CZS-10 (10 % SnS₂ on ZrO₂ (25 %)/g-C₃N₄) demonstrated the highest photocatalytic activity, achieving 99.5 % degradation of RhB in 120 min and 89.44 % degradation of CP in 180 min. The improved performance is attributed to efficient charge separation and enhanced light absorption in the ternary nanocomposites. Active species analysis revealed that photogenerated holes and electrons were primarily responsible for RhB degradation, while oxygen radicals and holes were crucial for CP degradation. The study also evaluated the effect of pH, reusability up to five cycles, and electrochemical properties through Motty-Schottky curves and EIS, revealing the increase in donor density and reduced charge resistance in the composites. This study emphasizes the promise of the developed heterojunction hybrid photocatalysts for affordable environmental remediation applications, providing an eco-friendly approach to effectively eliminate water pollutants under visible light.