High-Throughput Screening Unveils a Novel Non-Janus MoSH Monolayer as a Promising Candidate for Catalysis

Experimentally determining the positions of hydrogen (H) atoms at the interface of two-dimensional (2D) MoSH monolayers remains challenging due to the light mass of H atoms. Previous studies on MoSH monolayers have been confined to Janus-structured models. In this work, we combined high-throughput screening and first-principles calculations to identify a stable reversed 2H-MoSH monolayer with a non-Janus structure. This structure features sulfur (S) and H atom layers that are symmetrically alternating and distributed on both sides of the molybdenum (Mo) atomic layer. Energetic, thermodynamic, and dynamic analyses confirm the robust stability of the reversed 2H-MoSH monolayer. Compared with Janus MoSH, the reversed 2H-MoSH exhibits higher binding energy with a value of -2.95 eV. Interestingly, we observed a structural phase transition from reversed 2H-MoSH to hybrid 1T'-MoSH at 600 K. Furthermore, we found that reversed 2H-MoSH exhibits high catalytic performance for oxygen evolution and hydrogen evolution, with overpotentials of 0.41 and -0.03 V, respectively. Our work not only expands the family of 2D transition metal dichalcogenides (TMDCs) but also proposes a promising candidate for future electronic and catalytic applications.