Enhanced visible light degradation of RhB in aqueous solution by using Sb₂S₃ modified with magnetic activated carbon

The removal of hazardous organic dyes (e.g., Rhodamine B) from wastewater is one of the current major environmental challenge, which is related to traditional photocatalysts with low efficiencies, poor stabilities, and complex recycle process. Herein, we presented the synthesis of a multifunctional magnetically recoverable composite of magnetic-activated carbon (MAC) in combination with antimony sulfide (Sb₂S₃) composite by which not only the visible-light-driven photodegradation efficiency was improved but also improved adsorption for the pollutants. Comprehensive spectral analysis, including X-ray diffraction and scanning electron microscopy, confirmed the successful synthesis of Sb₂S₃ photocatalyst-modified by MAC (PMAC). SEM analysis showed high particle porosity, while elemental analysis confirmed the successful incorporation of Sb₂S₃ nanoparticles onto MAC. N₂ vapor adsorption experiments revealed a BET surface area of 271 m²/g for PMAC, characterizing it as a porous material based on pore diameter analysis. The composite exhibited thermal stability between 0 and 100 °C, evident from TG profiles. Moreover, the adsorption studies best fitted Langmuir isotherm model indicating monolayer adsorption of dye molecules on adsorbent. The photocatalytic degradation of RhB was investigated using PMAC focusing on effect of catalyst loading, pH, and initial dye concentration on decolorization and degradation. Complete decolorization occurred within 30 min, followed by full degradation after 60 min. The photodegradation of the model dye by PMAC followed second-order kinetics. The as-synthesized photocatalyst can be easily removed post-treatment using a simple magnet, enhancing its practical applicability in water treatment processes.