Computational methods. The adsorption behaviors of C6H6 and CH3 molecules on 3C-SiC (111) and (110) planes were studied by quantum chemical calculation via the software Gaussian 16 . The (111) and (110) surfaces are modeled using Si15C15 and Si16C16 clusters, respectively, both containing 4 atomic planes. To preserve the bulk structure of SiC, the lateral and bottom side of the clusters are saturated with hydrogen atoms. As for the top surface, the (111) plane is terminated with Si atoms without H-saturation, while on the (110) plane only C atoms are saturated with hydrogen. The geometries of these clusters are optimized by calculations based on density functional theory (DFT) using B3LYP functionals with the 6-31G(d, p) basis set and the empirical dispersion corrections D3 proposed by Grimme et al. The spin configuration giving the lowest energy and the least distorted structure were used for each cluster. The adsorption energy, Eads, is calculated as follows: