Strain-induced stabilization of Al functionalization in graphene oxide nanosheet for enhanced NH3 storage

Strain effects on the stabilization of Al ad-atom on graphene oxide (GO) nanosheet as well as its implications for NH3 storage have been investigated using first-principles calculations. Tensile strain is found to be very effective in stabilizing the Al ad-atom on GO. It strengthens the C–O bonds through an enhanced charge transfer from C to O atoms. Interestingly, Al's stability is governed by the bond strength of C-O rather than that of Al-O. Optimally strained Al-functionalized GO binds up to 6 NH3 molecules, while it binds no NH3 molecule in unstrained condition.