Abstract
We employed density functional theory to characterise H2S adsorption, and dissociation on the pristine and Stone–Wales (SW) defected BC3 graphenes. H2S is predicted to be weakly adsorbed on the pristine graphene with the adsorption energy of about 7.11 kcal/mol. Two types of SW defects were generated by rotating a C–C bond (SW-CC) or a B–C bond (SW-BC) by about 90°. We predict that, in contrast to SW-BC, dehydrogenation of H2S is energetically more favourable on the SW-CC compared to the associative adsorption. It is also found that SW-CC formation is more favourable than the formation of SW-BC. Molecular adsorption of H2S on both of the SW defected sheets is more favourable than that on the pristine sheet. The preferable adsorption process on the SW-BC and SW-CC defected graphene sheets is via associative and dissociative mechanisms, respectively. Furthermore, the highest occupied molecular orbital and lowest unoccupied molecular orbital energy gap of the SW-BC defected sheet is highly sensitive to the adsorption process which may be used for the detection of H2S.
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