Large-scale molecular dynamics simulations of negative Poisson’s ratio in hydrogenated biphenylene

This study was conducted to investigate the effect of hydrogenation on the Poisson’s ratio of biphenylene. By combining large-scale molecular dynamics simulations with a stochastic structure generation method, this study revealed that the Poisson’s ratio of biphenylene can shift from positive to negative as the degree of hydrogenation is adjusted. Specifically, at lower hydrogenation levels, the Poisson’s ratio decreases with increasing hydrogenation, eventually exhibiting a negative Poisson’s ratio at 40% to 50% hydrogenation. However, as hydrogenation progresses further, the negative Poisson’s ratio effect diminishes. The occurrence of negative Poisson’s ratio in hydrogenated biphenylene is attributed to a pronounced ripple effect induced by hydrogenation. Under tensile strain, the suppression of ripples reduces contraction in the direction perpendicular to the applied stretch. Moreover, the findings highlight a strong correlation between the ripple effects in the structure and the percentage of hydrogenation. These results demonstrate that hydrogenation serves as an effective approach to modulate the Poisson’s ratio of biphenylene, enabling its transition from positive to negative.