Thioglycolic acid assisted hydrothermal growth of SnS 2D nanosheets as catalysts for photodegradation of industrial dyes.

We present our work on the rapid hydrothermal synthesis of highly crystalline 2D SnS nanostructures. An innovative idea is used in which thioglycolic acid is the sulfur precursor source. Structural studies indicate the material has grown in a single-phase orthorhombic structure. The single-phase formation of the material is also confirmed from the rietveld refinement of the experimental XRD data and by raman spectroscopic analysis. Morphological studies show the formation of 2D sheets having thickness in the nanoscale (100-150 nm) dimensions. Optical absorbance studies show the material is visible-light active exhibiting an indirect bandgap of 1.1 eV and direct band gap ∼1.7 eV. Density functional theory calculations support the experimental bandgap results. Photocatalytic activity of the nanosheets was investigated against methylene blue (MB), rhodamine B (RhB) and methyl orange (MO) dyes employing a solar simulator as the source of photons (light source). The nanosheets were found to photodegrade 80% of MB, 77% of RhB and 60% of MO in 120 min of light illumination. Reusability and post catalytic properties affirm the durability and stability of the nanosheets, which is very important in the context of waste water treatment considering the toxic nature of the effluents from dye industries.

MoB2 Driven Metallic Behavior and Interfacial Charge Transport Mechanism in MoS2/MoB2 Heterostructure: A First-Principles Study.

We have performed the density functional theory calculations on heterostructure (HS) of MoS2 and MoB2 monolayers. The aim of this study is to assess the influence of MoB2 on electron transport of adjacent MoS2 layer. In present investigation we predict that the electronic properties of MoS2 monolayer is influenced by 4d-states of Mo in MoB2 monolayer. Whereas, the B atoms of MoB2 and S atoms of MoS2 exhibit overlapping of intermediate atomic orbitals thereby collectively construct the interfacial electronic structure observed to be metallic in nature. From charge density calculations, we have also determine that the charge transfer is taking place at the interface via B-2p and S-3p states. The bonds at the interface are found to be metallic which is also confirmed by adsorption analysis. Thermoelectric performance of this HS is found be in good agreement with available literature. Low Seebeck coefficient and high electrical conductivity further confirms the existence of metallic state of the HS.