Two-Dimensional Transition Metal Silicate Formed on Ru (0001) by Hydrogenation*

Two-dimensional transition metal silicates are dynamically stable materials with interesting magnetic and piezoelectric properties which can render them useful for further applications [1]. Bottom-up synthesis of these materials has been challenging due to strong overlayer-substrate interactions, which prevents the exfoliation of the overlayer. Here, using density functional theory calculations, we systematically investigate the hydrogenation of the overlayer as a way to decrease the substrate and overlayer interactions [2]. Using the Fe₂Si₂O₈·O/Ru(0001) structure as our starting point from Wlodarczyk et al.[3], we study hydrogenation levels up to Fe₂Si₂O₉H₄·Ru(0001). Structural and thermodynamical properties are studied at different hydrogenation levels to show under which conditions, the exfoliation can be feasible. Simulated core-level shifts show that Fe is primarily in a 3+ state through the hydrogenation of Fe₂Si₂O₈·O/Ru(0001). Simulated reflection adsorption infrared spectroscopy (RAIRS) yields distinctive shifts in vibrational properties with increasing hydrogenation which can guide experiments.

[1] K. Saritas et al. "Magnetism and piezoelectricity in stable transition metal silicate monolayers" Phys. Rev. Mat. (accepted, 2021). 

[2] K. Saritas et al., https://arxiv.org/abs/2110.05629

[3] R. Wlodarczyk et al., J. Am. Chem. Soc., 135, 51, 19222, (2013).