Prior to pore morphology analysis, all the samples were degasser under vacuum for 12 h to effectively drive out the residual gas and moisture.
The nitrogen adsorption
and desorption isotherms at 77 K were collected at relative pressures
(p/p0) ranging from 0.005 to 0.995. In this work, the specific surface
area, pore volume and pore size of each sample were analyzed based
on the nitrogen adsorption and desorption data. Further calculative
details can be found in