Benchmarking the high conductive two-dimensional layered structured NbS ₂ , ZrS ₂ , ReS ₂ and NbSe ₂ materials with zero energy bandgap ( <i>E</i> _g ) for photocatalytic application: a DFT study

Two-dimensional materials are among the most scientifically accessible materials in material science at the beginning of the twenty-first century. There has been interest in the monolayer transition metal dichalcogenide (TMDC) family because of its large active site surface area for UV photons of light for wastewater treatment. In the present work, density functional theory (DFT) is utilized to model the optical, structural and electrical properties of TMDCs such as NbS₂, ZrS₂, ReS₂ and NbSe₂ using the GGA-PBE simulation approximation. Based on DFT calculations, it is determined that NbS₂, ZrS₂, ReS₂ and NbSe₂ have zero energy bandgap (<i>E</i> _g). The additional gamma-active states that are generated in NbS₂, ZrS₂, ReS₂ and NbSe₂ materials aid in the construction of the conduction and valence bands, resulting in a zero <i>E</i> _g. In the ultraviolet (UV) spectrum, the increase in optical conductance peaks from 4.5 to 15.7 suggests that the material exhibits stronger absorption or interaction with UV light due to the excitation of electronic transitions or inter-band transitions. The highest optical conductivity and absorbance of two-dimensional TMDCs NbS₂, ZrS₂, NbSe₂ and ReS₂ show 2.4 × 10⁵, 2.5 × 10⁵, 2.8 × 10⁵ and 7 × 10⁵ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mstyle> <mml:mrow><mml:msup><mml:mi>Ω</mml:mi> <mml:mrow><mml:mo>-</mml:mo> <mml:mn>1</mml:mn></mml:mrow> </mml:msup> <mml:mspace></mml:mspace> <mml:mi>c</mml:mi> <mml:msup><mml:mi>m</mml:mi> <mml:mrow><mml:mo>-</mml:mo> <mml:mn>1</mml:mn></mml:mrow> </mml:msup> </mml:mrow> </mml:mstyle> </mml:math> , respectively. The TMDC family, including two-dimensional TMDCs NbS₂, ZrS₂, NbSe₂ and ReS₂, is known for its unique electronic and optical properties. Their layered structure and high surface area make them excellent candidates for applications involving light absorption and photodetection. These materials reduce photon recombination and improve charge transport, making them suitable for photocatalytic and photoanode applications.