Interface engineered MoS2 based nanoheterostructures as efficient photocatalysts and catalysts for organic pollutant remediation

In this study, a MoS 2 /Cu 2 O nanoheterostructure was synthesized and evaluated for its photocatalytic performance in the degradation of hazardous organic dyes, namely Rhodamine B (RhB), Bromophenol Blue (BpB), and 4-nitrophenol (4NP). The composite was fabricated by hydrothermally synthesized MoS 2 combined with Cu 2 O nanoparticles under controlled conditions. Structural and morphological analyses via X-ray diffraction, Field emission scanning electron microscopy, transmission electron microscopy, atomic fluorescence microscopy, Fourier transform infra-red spectroscopy and Raman spectroscopy confirmed the successful formation of a well-integrated heterostructure. Ultra violet diffuse reflectance spectral analysis revealed bandgap energies of 1.78 eV for MoS 2 (molybdenum disulfide) and 1.82 eV for Cu 2 O (cuprous oxide). The optimized MoS 2 /Cu 2 O composite exhibited a significant enhancement in photocatalytic activity, for Rhodamine B, and Bromophenol Blue under irradiation of 420 nm wavelength of light. The catalytic reduction of 4-nitrophenol by sodium borohydride (NaBH 4 ) was efficiently facilitated by a MoS 2 /Cu 2 O nanoheterostructure, demonstrating enhanced electron transfer capabilities and high catalytic activity. The degradation kinetics followed the Langmuir–Hinshelwood pseudo-first-order model. The mechanism is attributed to a Z-scheme electron transfer mechanism, in which the photoexcited electrons in Cu 2 O recombine with holes in MoS 2 , allowing the retention of active charge carriers. The degradation of RhB, BpB and 4NP followed pseudo first order kinetics with rate constant values of 0.0919 min -1 , 0.0955 min -1 and 0.27 min -1 respectively. Superoxide radicals ( • O 2 - ) were identified as the primary reactive species responsible for dye degradation. The composite also showed excellent stability and reusability over multiple cycles. These results demonstrate that the MoS 2 /Cu 2 O heterostructure is a promising photocatalyst for wastewater treatment applications. • A MoS 2 /Cu 2 O nanoheterostructure was successfully synthesized and confirmed through XRD, FESEM, TEM, AFM, FTIR, and Raman analyses. • The composite showed significantly enhanced photocatalytic degradation of Rhodamine B and Bromophenol Blue under 365 nm light irradiation. • Demonstrated high catalytic efficiency in the reduction of 4-nitrophenol using NaBH 4 , attributed to improved electron transfer properties. • A Z-scheme electron transfer mechanism was proposed, supported by the involvement of superoxide radicals (•O 2 - ) and Langmuir–Hinshelwood kinetics. • The heterostructure exhibited excellent structural stability and consistent catalytic activity over multiple reuse cycles, highlighting its potential for wastewater treatment.