The effect of hydrogen adsorption on Ti2AlV (110) surface: First-principle density functional theory study

The titanium alloy material is still the most promising material application in the gas turbine, energy, chemical, and biomedical industries because of its unique and its exceptional strength-to-weight ratio. However, corrosion and the effects of hydrogen embrittlement (HE) are still major and critical factors to material failure and restriction in many applications. First-principle density functional theory was used in the current study to examine the hydrogen adsorption on the surface of Ti 2 AlV. Adsorption at different surface sites was used to investigate the effect of hydrogen on the surface of Ti 2 AlV (110) by calculating adsorption energy, work function, and charge density distribution. All the adsorption energies were found to be negative, indicating an exothermic process and spontaneous reaction. More importantly, the effect of Van der Waals forces and dispersion correction was investigated on all the adsorption sites, with all sites showing the adsorption energies strength of E ads DFT−D >E ads DFT . It was revealed that the estimated adsorption energies vary with the adsorption surface sites, with the Ti-V bridge site having the highest adsorption energy. Additionally, it was found that the Al element is more resistant to H adsorption compared to the Ti and V atoms. The calculated charge density distribution projected the electron depletion on the surface atoms and accumulation on the H atom. Furthermore, H adsorption was found to alter the surface work function of Ti 2 AlV. Current findings revealed that the surface of Ti 2 AlV is more likely to form HE at the Ti-V site.