STUDY OF HYDROCARBON GROUP ABSORPTION ON DIFFERENT DIAMOND CRYSTAL SURFACES

The adsorption configuration and adsorption energy of various hydrocarbon groups adsorbed by a diamond base model with crystal orientations of (100), (111), and (110) are calculated based on the first principle of density functional theory. The results indicate that the adsorption energy follows the order (110) < (100) < (111). The (100) crystal orientation exhibits the strongest adsorption interaction for CH 3 , whereas the (111) orientation is more favorable for CH 2 adsorption. Additionally, the (110) crystal orientation shows enhanced bonding interactions with the CH group. The magnitude of energy barrier of the dehydrogenation reaction was found to be (110) < (100) < (111) based on the transition state search and calculation of the extracted hydrogen atoms following the adsorption of CH 3 on the diamond surface of three different crystal orientations. The larger the adsorption energy of the hydrocarbon groups adsorbed to the diamond surface of different crystals, the larger the energy barrier of the dehydrogenation reaction. The findings indicate that the distinct crystal orientation has an impact on the dehydrogenation reaction’s rate and complexity. The subsequent deposition development of diamond will be impacted by the competing growth of distinct crystal orientations, resulting in the formation of diamond coatings with distinct appearances and physical properties.