Heterojunction of TiO2 nanoparticle embedded into ZSM5 to 2D and 3D layered-structures of MoS2 nanosheets fabricated by pulsed laser ablation and microwave technique in deionized water: structurally enhanced photocatalytic performance

In this paper, we report a one-step, fast and ecofriendly synthesis of layered-structured MoS2 nanosheets (NSs) by pulsed laser ablation in liquids (PLAL). The resultant MoS2 NS was used to construct TiO2-ZSM5-MoS2 nanocomposite. After impregnating ZSM5 structures with TiO2 nanoparticles (TiO2 NPs), heterojunctions of MoS2 NS were made on the fabricated TiO2-ZSM5 by microwave treatment at high temperature and pressure. Formation of 2D and 3D structures of MoS2 was shown. Crystal structure, size and shape of the synthesized nanostructures were studied by X-ray powder diffraction (XRD) and microscopy techniques. Results of the structural analysis showed that the PLAL constructed MoS2 NSs mainly had a layered morphology several micrometers in size with horizontally and vertically aligned layers. The hexagonal crystalline structure of MoS2 NS, anatase TiO2 NPs and microcrystalline ZSM5 structures were determined by XRD, high-resolution transmission electron microscopy (HRTEM) and fast Fourier transform (FFT) analysis. Formation of MoS2 NS was further shown with Raman peaks at approximately 385.30 and 407.50cm(-1) corresponding to the E1 2g and A1g vibrational modes of MoS2 NS. The PLAL synthesized MoS2 NS demonstrated broad absorption in the visible region. Photocatalytic activity of TiO2-ZSM5-MoS2 nanocomposite was tested with arsenite. TiO2-ZSM5-MoS2 nanocomposite exhibited approximately 100% arsenite photo-conversion to arsenate.