Ternary Composite-Enabled Photocatalytic Degradation of Multi-class Pollutants: Case Study of Congo Red, Diclofenac Sodium, and Pendimethalin

Water remediation has become a hot subject of study due to textile, pharmaceutical, and agricultural discharge to the water bodies. Photocatalysis with photocatalyst having favorable structure, reduced charge carrier recombination and ability to harness UV–Visible spectrum has emerged as efficient way to completely mineralize the persistent organic pollutants (POPs) (Sharma et al. in J Environ Chem Eng 9(5):105812, 2021; Chawla et al. in Coord Chem Rev 491:215246, 2023). In this research, we reported the synthesis of SnO₂/Fe₂O₃/MoS₂ ternary composite. The motive of the composite formation is to harvest the entire solar spectrum with prolonged electron–hole recombination. The band gap has reduced from 3.46 to 2.30 eV with the formation of SnO₂/Fe₂O₃/MoS₂ ternary composite. The ternary composite exhibited an excellent photocatalytic activity of 95% against Congo red after 80 min at a rate constant of 0.018 min⁻¹. Moreover, the composite showed a photocatalytic activity of 85% and 93% against diclofenac sodium and pendimethalin at a rate constant of 0.017 min⁻¹ and 0.02 min⁻¹ respectively. Through trapping experiments, we determined that hydroxyl radicals scavenging had reduced the photocatalytic degradation of Congo red, diclofenac sodium and pendimethalin to 25%, 22%, and 15% respectively. Beyond its exceptional photocatalytic degradation capabilities, the SnO₂/Fe₂O₃/MoS₂ ternary composite also ushered in new possibilities for utilizing wide band gap materials reinforced with visible light active materials along with 2-D materials. Graphical Abstract: (Figure presented.)