Ab initio Prediction of Stability and Photocatalytic Performance of Transition Metal Oxide Nanoscrolls

Metal oxides have been ideal host materials for a wide range of applications like catalysis, energy storage, and electronic devices, owing to their inherent stability and easy tunability of their properties. In recent times, there has been a significant effort to couple these properties with the effects of confinement that is unique to lower dimensional structures like 2D materials, in order to further enhance the range of applications of these materials. The primary bottleneck in these efforts is the lack of van der Waals layered bulk structures for oxides that could provide an immediately apparent cleavage plane^[1,2] to form low-dimensional oxides. A recent work by Wang et al^[3], eliminates this prerequisite by starting with layered transition metal dichalcogenide(TMDC) as a precursor, followed by a controlled oxidation of the top layers, resulting in quasi 1D nanoscrolls of a corresponding transition metal oxide. In this work, we use first-principles calculations to build a method to establish the feasibility of forming oxide nanoscrolls from TMDC precursors. We first devise a theoretical screening method to identify potential precursor TMDCs by an extensive search of current materials databases. We then proceed to find DFT-calculated physical parameters of possible nanoscroll structures and consequently use them to fit a physio-mechanical model of scrolls in order to predict the exact geometry of these structures. We finally use ab initio molecular dynamics calculations coupled with GW-calculated electronic structures to establish the performance of these structures as materials for photocatalytic water-splitting and H₂ storage.

[1] Guo, Yuqi, Gupta, A. et al. "Exfoliation of boron carbide into ultrathin nanosheets." Nanoscale 13.3 (2021): 1652-1662.

[2] Gupta, A., T. Biswas, and A. K. Singh. "Anomalous stability of non-van der Waals bonded B4C nanosheets through surface reconstruction." Journal of Applied Physics 132.24 (2022).

[3] Chu, Ximo S., et al. "Formation of MoO₃ and WO₃ nanoscrolls from MoS₂ and WS₂ with atmospheric air plasma." Journal of Materials Chemistry C 5.43 (2017): 11301-11309.