Hydrogen adsorption on α-Fe 2 O 3 nanorods: A molecular dynamics simulation study

Gas adsorption primarily occurs on the surface of sensitive materials, making the surface structure of the material closely related to this process. High-quality sensitive materials require a high surface area and high surface activity. Nanomaterials, due to their extremely high surface area, exhibit superior sensing performance. In this study, we designed four different types of α-Fe 2 O 3 nanorods (standing nanorod, nano-zigzag, surface-threaded, sugar-gourd-shaped) and employed reactive molecular dynamics to investigate the adsorption performance of these nanorods for hydrogen. The results indicate that, compared to standing nanorod, the nano-zigzag structures exhibit poorer adsorption efficiency for hydrogen, while the surface-threaded and sugar-gourd-shaped structures demonstrate excellent adsorption performance. The width of thread on surface-threaded nanorods has certain influence on the adsorption rate but has minimal impact on the adsorption amount. The adsorption efficiency of sugar-gourd-shaped nanorods is notably affected by the diameter of the spheres. Within the range of 300– 600 K, increasing temperature is detrimental to the adsorption of hydrogen on the α-Fe 2 O 3 nanostructured surfaces. These findings provide useful information on the structural design of gas sensors at the nanoscale.