Strain Modulated Electronic and Photocatalytic Properties of MoS₂/WS₂ Heterostructure: A DFT Study

Abstract

Solar energy-driven hydrogen generation through the water-splitting (WS) method is an efficient approach to conquer the worldwide energy shortage in the near future and environmental pollution by employing a suitable semiconductor photocatalyst. Herein, structural, electronic, and photocatalytic properties of MoS 2 /WS 2 heterobilayer are thoroughly inspected with biaxial strain for their use in WS applications. Furthermore, among the six considered stacking patterns of the heterostructure (HS), conf-1 has the most stable structure due to its lowermost interlayer binding energy of −18.07 meV/Å 2 . In addition, MoS 2 /WS 2 HS shows type II band alignments, where MoS 2 contributes to the conduction band minima (CBM), and the WS 2 monolayer is located at valence band maxima (VBM) positions, respectively, in the HS. Moreover, owing to the smaller effective mass values of the HS than to the constituent monolayers, MoS 2 /WS 2 HS has excellent carrier mobility, which further suggests faster migration of charge carriers and a lower recombination rate during the WS process. An enhanced visible light absorption intensity of 8.3 × 10 5 cm −1 has been observed for the HS rather than the MoS 2 (6.33 × 10 5 cm −1 ) and WS 2 (7.51 × 10 5 cm −1 ) monolayers. The HSs under the biaxial tensile strain of 1% and compressive strain up to 4% are attended suitable CBM and VBM positions with water reduction (WRP) and oxidation potentials (WOP) that are appropriate for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Moreover, under tensile strain, the absorption edges of HS are moderately red-shifted, which makes it as a potential candidate for solar energy harvesting. Our findings open a new research interest in exploring these kinds of 2D vdW HSs experimentally for a WS mechanism, and modulation of their activity can be done by external strain.

Characterization of Type I/II g-C3N4/MoS2 van der Waals Heterostructures: A New Theoretical Insight

“…Similar to graphene, the MoS 2 monolayer has a honeycomb structure. The lattice constants of the unit cell for g-C 3 N 4 and MoS 2 were calculated to be 4.79 and 3.19 Å, respectively, which are in line with early reports. ,− The optimized configurations are shown in Figure , parts a and b.…”

Tunable Electronic Properties, Carrier Mobility, and Contact Characteristics in Type-II BSe/Sc2CF2 Heterostructures toward Next-Generation Optoelectronic Devices

“…One can find that the interlayer distances are close for different stacking patterns. The similar observation was also occurred in other 2D vdW-based heterostructures. , Pattern B exhibits the shortest interlayer distance compared to the other stacking patterns.…”

“…The similar observation was also occurred in other 2D vdW-based heterostructures. 61,62 Pattern B exhibits the shortest interlayer distance compared to the other stacking patterns. Furthermore, the structural, mechanical, dynamical, and thermal stabilities of the BSe/Sc 2 CF 2 heterostructure can be confirmed by calculating binding energy, phonon dispersions, and AIMD simulations.…”

Visible Light-Driven Photocatalytic Degradation of Methylene Blue Dye Using a Highly Efficient Mg–Al LDH@g-C3N4@Ag3PO4 Nanocomposite

“…As a result, the generation and transportation of charge carriers to the electrolyte under light illumination are facilitated. 63,64 The above observation cooperatively validates that the Mg−Al LDH@g-C 3 N 4 30@Ag 3 PO 4 5 composited from Mg−Al LDH, Mg−Al LDH@g-C 3 N 4 30, and Ag 3 PO 4 aids in facilitating the efficacious transferring and separating charge carriers, thus enhancing the efficiency of the photocatalytic activity.…”