First principles evaluation on photocatalytic suitability of 2H structured and [0001] oriented WS2 nanosheets and nanotubes
| dc.contributor.author | Zhukovskii, Y. F. | |
| dc.contributor.author | Piskunov, Sergei | |
| dc.contributor.author | Evarestov, R. A. | |
| dc.date.accessioned | 2020-08-19T17:26:51Z | |
| dc.date.available | 2020-08-19T17:26:51Z | |
| dc.date.issued | 2019 | |
| dc.description | This study was supported by the EC ERA.Net RUS Plus Project No. 237 WATERSPLIT. R.E. acknowledges the financial support provided by the Russian Foundation for Basic Research (grant N 17-03-00130a) and High Performance Computer Center of St. Petersburg University for the assistance. The authors are indebted to D. Bocharov, O. Lisovski and E. Spohr for stimulating discussions. | en_US |
| dc.description.abstract | Pristine WS2 multilayer nanosheets (NSs), which thickness h NS varies from 1 to 12 monolayers (MLs), as well as single- and multi-walled nanotubes (SW and MW NTs) of different chirality, which diameter d NT exceeds 1.9 nm, display photocatalytic suitability to split H2O molecules. Obviously, such a phenomenon can occur since the band gap of these nanostructures corresponds to the energy range of visible light between the red and violet edges of spectrum (1.55 eV < Δϵgap < 2.65 eV). For all the studied WS2 NSs and NTs, the levels of the top of the valence band and the bottom of the conduction band must be properly aligned relatively to H2O oxidation and reduction potentials separated by 1.23 eV: ϵ VB < ϵO2/H2O < ϵH+/H2 < ϵ CB. The values of Δϵgap decrease with growth of h NS and increase with enlargement of dNT. 1 ML nanosheet can be considered as a limit of infinite SW NT thickness growth (d NT→∞), which band gap increases up to ∼2.65 eV. First principles calculations have been performed using the hybrid DFT-HF method (HSE06 Hamiltonian) adapted for 2H WS2 bulk. The highest solar energy conversion efficiency (15-18%) expected at Δϵgap = 2.0-2.2 eV (yellow-green range) has been found for 2 ML thick (stoichiometric) WS2 (0001) NS as well as WS2 NTs with diameters 2.7-3.2 nm (irrespectively on morphology and chirality indices n of nanotubes). Moreover, unlike discrete variation of hNS magnitudes, tuning of d NT values provides much higher energy resolution. | en_US |
| dc.description.sponsorship | Russian Foundation for Basic Research N 17-03-00130a; European Commission EC 237 WATERSPLIT; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART² | en_US |
| dc.identifier.doi | 10.1088/1757-899X/503/1/012002 | |
| dc.identifier.issn | 1757-8981 | |
| dc.identifier.uri | https://dspace.lu.lv/dspace/handle/7/52417 | |
| dc.language.iso | eng | en_US |
| dc.publisher | Institute of Physics Publishing | en_US |
| dc.relation | info:eu-repo/grantAgreement/EC/H2020/739508/EU/Centre of Advanced Material Research and Technology Transfer/CAMART² | en_US |
| dc.relation.ispartofseries | IOP Conference Series: Materials Science and Engineering;503 (1), 012002 | |
| dc.rights | info:eu-repo/semantics/openAccess | en_US |
| dc.title | First principles evaluation on photocatalytic suitability of 2H structured and [0001] oriented WS2 nanosheets and nanotubes | en_US |
| dc.type | info:eu-repo/semantics/conferenceObject | en_US |