Data-Driven Discovery of Transition Metal Dichalcogenide-Based Z-Scheme Photocatalytic Heterostructures

Abstract

The Z-scheme heterostructure is a highly promising photocatalyst for its unique electronic structure. However, a thorough examination of the heterostructure design space through experimental or computational means is prohibitively expensive. Here, we propose a highly efficient data-driven approach for fast discovering van der Waals (vdW) Z-scheme heterostructures, bypassing the need for costly calculations and experimentation. By conducting highthroughput calculations with the Heyd−Scuseria−Ernzerhof hybrid density functional (HSE06), we first generate a variety of data of electronic structures for 18 experimentally synthesized 2D transition metal dichalcogenides (TMDs) and 20 of 153 heterostructures (constructed with the 18 TMDs). Using these data, we develop an innovative and robust descriptor: Allen "material" electronegativity. Leveraging this descriptor, we identify 27 2D vdW Z-scheme heterostructures from the pool of 153 heterostructures without expensive HSE calculations. We finally refine our findings by selecting six Z-scheme heterostructures with minimal lattice mismatch, further validating them using high-fidelity ab initio calculations and studying their optical absorption. Our research not only paves the way for discovering high-performance Z-scheme photocatalysts using data-driven methods but also contributes a universal charge transfer mechanism for vdW device applications.

Data-Driven Discovery of Intrinsic Direct-Gap 2D Materials as Potential Photocatalysts for Efficient Water Splitting

“…To date, several 2D materials have been explored and applied as photocatalysts for water splitting, including transition-metal dichalcogenides (TMDs) (such as MoS 2 ), g-C 3 N 4 , phosphorene, as well as 2D MOF/COF materials . In addition, bilayers of different 2D materials have been studied, to explore their functionality in a Z-scheme, − for instance.…”

“…Given the selection of the final candidates, one could use these in a study focused on the OER and HER. Note, however, that such a study should also include lattice defects and 2D edges, as such structures can significantly improve catalytic properties. , In addition, the 16 candidates identified here could be used in a study to investigate their feasibility in a Z-scheme, by constructing bilayers and heterojunctions of different materials …”

“…55,56 In addition, the 16 candidates identified here could be used in a study to investigate their feasibility in a Z-scheme, by constructing bilayers and heterojunctions of different materials. 22 54 Through extensive ML model training utilizing a large data set of DFT calculations at the PBE level, key properties such as the band-gap character (direct or indirect), band-gap values, band edges with respect to the vacuum level, and magnetic states were predicted and collected in V2DB. Here, we initiate our screening process of direct-gap 2D photocatalysts on the basis of ML-predicted properties.…”

Construction of Active and Stable Photoelectrodes via Complementary Coupling of Two-Dimensional Narrow- and Wide-Bandgap Nanosheets

“…Transition metal dichalcogenides (TMDCs) based on Mo, W, Sn, Zr, Hf, Pd, and Pt are characterized by narrow bandgaps (1.5–2.5 eV) as well as well-situated valence band maximum (VBM) and conduction band minimum (CBM) for essential processes such as hydrogen evolution, oxygen evolution, carbon dioxide reduction, and nitrogen fixation . Despite their attractive features, research on photocatalysts based on ultrathin TMDCs has been mostly limited to computational studies − because the synthesis of NSs with sufficient quality is a challenging task. In fact, photoanodes with MoS 2 or WS 2 NSs synthesized using common alkali metal intercalation methods followed by a thermally driven phase transition from a metastable metallic 1T phase to a semiconducting 2H phase yield very small values of absorbed photon-to-electron conversion efficiency (APCE) below 0.2% in both water and sulfite oxidation reactions, , although the metallic 1T phase TMDC NSs are suitable as electrocatalysts and cocatalysts. , A recently developed electrochemical (EC) exfoliation technique based on bulky amine intercalation could overcome this issue, , as the EC exfoliation of TMDCs directly yields NSs featuring high crystallinity and a defect density as low as that of TMDC crystals obtained using state-of-the-art vacuum deposition methods.…”