Characterization of 3D Lattice from Transition Metal Dichalcogenides for Sensor Applications

  • Abdullah Mahmoud Solayman

Student thesis: Master's Thesis

Abstract

Materials are the core of any industry as they govern the performance of the products in targeted applications. A decade after the discovery of graphene, two-dimensional (2D) materials, a new class of materials, started to emerge. These layered nano-materials of atomic thickness have exceptional mechanical, electrical, and optical properties and thus anticipated to have a plethora of technological applications. In this work we have synthesized meso-scaled three-dimensional (3D) structures based on 2D heterogeneous nano-materials and experimentally investigated their electro-mechanical behavior towards pressure sensing, along with their microstructure using different characterization methods. Three types of lattices with different relative densities fabricated from both MoS2 and the heterostructure rGO/MoS2, were characterized. Results from x-ray diffraction (XRD) proved that MoS2 was successfully synthesized, with peaks at the double angle of 15, 35, and 60o . The hetero lattices of rGO/MoS2 were also successfully fabricated, with all the MoS2 peaks shown in the XRD spectrum, in addition to the angle 15o , indicating the existence of reduced graphene oxide (rGO). Scanning electronic microscopy (SEM) images showed the layers of both rGO and MoS2, which was not observed in the neat MoS2 lattice. MoS2 lattice showed elastic modulus of 62 kPa, 150 kPa, and 136.4 kPa for the 5 unit-unit cells and 7% relative density (RD), 5 unit-unit cells and 20% RD, and 10 unit-unit cells and 20%RD, respectively, under compressive loading. With the rGO/MoS2 heterostructure the elastic modulus increased to 388.8, 222.2, and 104.16 kPa. Piezoelectric sensors were fabricated with the 2D material lattices together with polydimethylsiloxane (PDMS). The response of the sensor increased by a factor of one million when rGO was added to the MoS2 lattice. A more uniform behavior dynamic testing was also added to the advantages of the heterostructure compared to the stand alone lattice of MoS2.
Date of AwardMay 2022
Original languageAmerican English

Keywords

  • 2D materials
  • MoS2 lattice
  • rGO/MoS2
  • Heterostructures
  • lattice
  • 3D lattice structures
  • triply periodic minimal surface.

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