High-Yield WS2 Synthesis through Sulfurization in Custom-Modified Atmospheric Pressure Chemical Vapor Deposition Reactor, Paving the Way for Selective NH3 Vapor Detection
: Malik, Shuja Bashir; Annanouch, Fatima Ezahra; D′Souza, Ransell; Bittencourt, Carla; Todorović, Milica; Llobet, Eduard
Publisher: American Chemical Society
: 2024
: ACS Applied Materials and Interfaces
: ACS Applied Materials & Interfaces
: 16
: 36
: 48585
: 48597
: 1944-8244
: 1944-8252
DOI: https://doi.org/10.1021/acsami.4c10077
: https://doi.org/10.1021/acsami.4c10077
: https://research.utu.fi/converis/portal/detail/Publication/457801771
Nanostructured transition metal dichalcogenides have garnered significant research interest for physical and chemical sensing applications due to their unique crystal structure and large effective surface area. However, the high-yield synthesis of these materials on different substrates and in nanostructured films remains a challenge that hinders their real-world applications. In this work, we demonstrate the synthesis of two-dimensional (2D) tungsten disulfide (WS2) sheets on a hundred-milligram scale by sulfurization of tungsten trioxide (WO3) powder in an atmospheric pressure chemical vapor deposition reactor. The as-synthesized WS2 powders can be formulated into inks and deposited on a broad range of substrates using techniques like screen or inkjet printing, spin-coating, drop-casting, or airbrushing. Structural, morphological, and chemical composition analysis confirm the successful synthesis of edge-enriched WS2 sheets. The sensing performance of the WS2 films prepared with the synthesized 2D material was evaluated for ammonia (NH3) detection at different operating temperatures. The results reveal exceptional gas sensing responses, with the sensors showing a 100\% response toward 5 ppm of NH3 at 150 °C. The sensor detection limit was experimentally verified to be below 1 ppm of NH3 at 150 °C. Selectivity tests demonstrated the high selectivity of the edge-enriched WS2 films toward NH3 in the presence of interfering gases like CO, benzene, H2, and NO2. Furthermore, the sensors displayed remarkable stability against high levels of humidity, with only a slight decrease in response from 100\% in dry air to 93\% in humid environments. Density functional theory and Bayesian optimization simulations were performed, and the theoretical results agree with the experimental findings, revealing that the interaction between gas molecules and WS2 is primarily based on physisorption.
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S.B.M. is supported by Martí-Franquès Research Grants Programme, Doctoral grants −2019, (2019PMF–PIPF-14). F.E.A. is a RYC2022-038111-I postdoctoral fellow from the Ramon y Cajal program. E. L. is supported by the Catalan Institution for Research and Advanced Studies via the 2018 Edition of the ICREA Academia Award. C. B is a research associate of FNRS-Belgium. M.T. and R.D. acknowledge CSC-IT Center for Science in Finland for supporting this work with high-performance computing resources. This work is supported by the Agencia Estatal de Investigación (AEI) under grant no. PDC2022-133967-100 and by AGAUR under grant no. 2021 SGR 00147. The HRTEM was partially funded by the operative program FEDER Catalunya 2014-2020 (IU16-015844).
