Abstract

This study models the diffusion of hydrogen in carbon nanotubes (CNTs) since it is interestingdue to its potential applications in various fields. In this report, a simulation of hydrogen diffusionin single-walled carbon nanotube under different diffusion times and temperatures is demonstratedto investigate the impact of diffusion times and temperatures on the concentration of hydrogen asa function of position into the carbon nanotube and to determine the temperature-independentdiffusion coefficient and activation energy needed to calculate the temperature-dependent diffusioncoefficient. The simulations are based on Fick’s first and Fick’s second law of diffusion, whichdescribes the change in concentration of a diffusing substance over time. A pre-defined surfaceconcentration is utilized to solve the diffusion equation numerically. The results show the highimpact of temperature on the diffusion process and the hydrogen concentration in the carbonnanotubes. In addition, the temperature-independent diffusion coefficient and activation energywere determined as 2.63 × 10−7 m^2/s and 833.6 J/mol, respectively.