Visible light driven Nd2O3/Mo(S,O)3-x·0.34H2O heterojunction for enhanced photocatalytic degradation of organic pollutants

Highlights: • Nd₂O₃/Mo(S,O)_3-x$·$0.34H₂O catalyst was synthesized by facile precipitation method. • Photocatalytic activity of catalysts was evaluated by MO, RhB, & MB degradation. • 20 mol% Nd₂O₃/Mo(S,O)_3-x·0.34 H₂O exhibited superior photocatalytic efficiency. • Formation of heterojunction enhances charge transfer efficiency of e^--h⁺ pairs. • O₂^–• , HO^• , and h⁺ majorly involved in photocatalytic degradation mechanisms. Developing low-cost and visible-light-driven metal oxide and sulfide-based photocatalysts for the degradation of organic dyes has been a major area of research to mitigate environmental pollution. In this study, a low-cost and facile precipitation method at low temperature of 95 °C was used to synthesize visible-light-driven Nd₂O₃/Mo(S,O)_3-x·0.34H₂O heterojunctions (NdMoOS). The crystal structure, elemental composition, optical, and electrical properties of as-prepared materials were investigated using various analytical techniques. Organic dyes of methyl orange (MO), Rhodamine B (RhB), and Methylene blue (MB) were selected as model organic pollutants to evaluate the photocatalytic efficiency of as-synthesized materials under visible light irradiation. 20 mol% NdMoOS nanocomposite showed excellent degradation efficiency and it decomposed 98.8%, 99.9%, and 99.8% of MO, RhB, and MB after 120 min, 90 min, and 90 min visible light irradiation, respectively. HPLC-MS analysis further confirms the complete removal of dyes. The formation of heterojunction, high charge separation, and low recombination rate of photoinduced e^--h⁺ pairs can contribute to the enhanced photocatalytic activity. Superoxide radicals (O^2–• ), hydroxyl radicals (HO^• ), and holes (h⁺ ) were identified as major oxidative species involved in the photocatalytic degradation mechanisms of MO, RhB, and MB dyes.