an individual fuel permeation from the one-?m-thick g-C3N4 membrane at home temperature and 1??bar. The inset shows the fuel selectivity for H2 around other gases. b Permeance and separation elements with the 1-?m-thick g-C3N4 membranes while in the equimolar combined-fuel permeation at home temperature and 1??bar. Inset exhibits the kinetic diamet