Photodegradation of rhodamine-B in aqueous environment using visible-active gC₃N₄@CS-MoS₂ nanocomposite

Rapid industrial expansion leads to environmental pollution especially in an aqueous environment. Photocatalytic degradation is one of the most efficient and environmentally friendly techniques used to treat industrial pollution due to its complete degradation capability of a variety of water contaminants to their non-toxic state. Graphitic carbon nitride (gC₃N₄) and molybdenum disulfide (MoS₂) provide efficient dye degradation, but MoS₂ has few disadvantages. Hence, chitosan (CS) supported gC₃N₄-MoS₂ hybrid nanocomposite was developed in this study to reduce these issues by accelerating the degradation of dye molecules such as rhodamine-B under visible light. The prepared gC₃N₄@CS-MoS₂ hybrid nanocomposite was thoroughly characterized using various analytical tools including FTIR, XRD, SEM, EDX, XPS, UV-Visible, and PL spectra. Several influencing parameters such as irradiation time, initial pH, dosage, and initial dye concentration were optimized by batch mode. The photodegradation of rhodamine-B could be induced by the heterogeneous gC₃N₄@CS-MoS₂-water hybrid nanocomposite. The narrow band gap of gC₃N₄@CS-MoS₂ (1.80 eV) makes it suitable for effective degradation of rhodamine-B due to more active in the visible region and attained its highest degradation efficiency of 99% after 40 min at pH 8 with minimum dosage of 60 mg. The possible degradation mechanism was tentatively proposed for rhodamine-B dye molecules from aqueous environment. The present work shows a novel photocatalyst for the purification and detoxification of dye molecules as well as other water contaminants found in polluted wastewater.