Experimental and theoretical DFT study of hydrothermally synthesized MoS2-doped-TiO2 nanocomposites for photocatalytic application

Abstract

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have shown considerable potential in photocatalytic applications. In the present research, the hydrothermal technique was used to prepare 2D MoS2, TiO2, and 2D layered structured with basic ration formulation as MoS2(1-x)TiO2x (X = 5 %, 10 %w/w) nanocomposites as an effective catalyst for degradation of aqueous methylene blue (M.B.) under controlled light radiations. The GGA-PBE computed approach was used to estimate the energy bandgap (Eg), electronic, and optical properties of 2D MoS2, TiO2, and MoS2(1-x)TiO2x (X = 5 %, 10 %) by density functional quantum computing simulation. The TiO2 nanospheres were efficiently decorated on the surface of layered of MoS2 and some of nanospheres mixed into layered matrix. Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) investigate the morphology and crystal phase structure of the samples. Experimental and theoretical results related the energy bandgap (Eg) of the 2D layered structure of MoS2, TiO2, and MoS2(1-x)TiO2x (5 %, 10 % w/w) shows a decrement trend 1.56, 2.4, 1.02, and 0.5 eV respectively with increasing doping percentages. The observed extra gamma active states of MoS2(1-x)TiO2x (X = 5 %, 10 % w/w) are found to be generated and contributed to the creation of conduction and valance bands as the result of the decremented of their energy bandgap. The optical conductance was increased from 2.5 to 9.8 Ω−1cm−1 with a bandgap decrement of 2.4–0.5 eV in the ultraviolet–visible spectrum region. Exploration of theoretical and experimental results of this work, the MoS2(1-x)TiO2x (5 %, 10 % w/w) show increment in absorbance from 1.4 × 105 to 4.5 × 105 cm−1 and 0.6 cm−1 to 1.25 cm−1 respectively. The most interesting result is at the peak of 650 nm wavelength, as it is considered a proficient photo-catalyst material due to the enhanced absorption surface area for exposure of light and decrement of the photo-generated charge recombination rate and increment of the charge transportation with the inclusion of TiO2. The breakdown of methylene blue within 15 min confirmed that the prepared MoS2(1-x)TiO2x nanocomposite was a stable, and cost-effective material for photocatalytic application.