Magnetic Fe3O4 supported MoS2 nanoflowers as catalyst for the reduction of p-nitrophenol and organic dyes and as an electrochemical sensor for the detection of pharmaceutical samples

Abstract

In the present study, Fe3O4 nanoparticles (NPs) supported MoS2 nanoflowers (Fe3O4–MoS2) are prepared by a simple and eco-friendly hydrothermal method and are well-characterized for their structure, morphology, size, phase composition, and magnetic property using XRD, FT‐IR, SEM, EDX, HR-TEM, SEM-elemental mapping and VSM techniques. As prepared Fe3O4–MoS2 showed good catalytic activity for the reduction of p-nitrophenol (p-NP), methylene blue (MB), and methyl orange (MO) dyes in the presence of NaBH4 in 10 min, 2 min, and 2 min with rate constants of 0.15 min−1, 0.88 min−1 and 0.53 min−1 respectively. Moreover, the Fe3O4–MoS2 catalyst was recovered magnetically in good yield and the recovered catalyst also showed a similar catalytic efficacy even up to nine cycles. Further, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements for Fe3O4–MoS2 electrode were performed in 1 M KOH aqueous electrolytes with (+0.50, −0.73 V) and (+0.10, −0.68 V) oxidation and reduction peaks in the reversible redox process respectively. The electrode exhibited a specific capacitance of 1.42 F g−1 basic electrolyte. EIS measurements showed a reduction in the charge transfer resistance. Modified carbon paste electrode using Fe3O4–MoS2 is used as a sensor for the detection of paracetamol (PCM), ascorbic acid (AA), hydrogen peroxide (HP), and tetracycline (TC) pharmaceutical samples, which showed well-separated peaks. These results indicate that the prepared Fe3O4–MoS2 has great potential to be developed as a catalyst and electrochemical sensor material for industrial applications.