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

Abstract

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 (O2–•), hydroxyl radicals (HO•), and holes (h+ ) were identified as major oxidative species involved in the photocatalytic degradation mechanisms of MO, RhB, and MB dyes.