MoS2 Nanosheets@Metal organic framework nanocomposite for enhanced visible light degradation and reduction of hazardous organic contaminants

Present research focuses on the environmental cleanup of hazardous organic pollutants that are discharged into the natural aquatic bodies which upshots an undesirable shift in the ecological balance. Recently, aromatic nitro compounds and hazardous organic dyes have been recognized as a threat to fauna, flora and human life forms. Therefore, effective and selective eradication of these hazardous pollutants from wastewater systems is a pressing global issue for the academic community. This study aims to design a MoS2 Nanosheets (NS)@Cu-MOF (MS−HK) catalyst via a convenient hydrothermal approach for the elimination of organic and aromatic nitro contaminants from wastewater effluent. Under visible light irradiation, this photocatalyst presented 96.4% removal efficiency for Rose Bengal (RB) dye within a short duration of 30 min, with a first order degradation rate constant of 0.12223 min−1and a catalyst loading of 240 mg/L. Again, the rate constant of the room temperature reduction of 2,4,6−trinitrophenol (TNP) using NaBH4 as a reducing agent, in presence of the prepared nanocatalyst was calculated to be 2.7 × 10−3 s−1. This excellent degradation efficiency could be due to the loading of HKUST-1 with a narrow band gap semiconductor MoS2 leading to enhanced visible light absorption, effective separation and transport of photoinduced h+−e− pairs that limit their recombination. The plausible photodegradation mechanism was supported by photoluminescence and radical trapping experiments. In addition, the impact of various inorganic ions, water matrices, environmental conditions, different dye molecules and mixed dye system was explored on the RB degradation of the synthesized catalyst. Meanwhile, the as-prepared MS−HK nanocomposite displayed significant stability during the photocatalytic experiments, as evident from XRD results, until four successive cycles maintaining an outstanding degradation efficiency of >89%.