Inhomogeneities of charge distribution in porous graphitic carbon nitride g-CxNy nanosheets Zefen Liang, Tianxiang He, Hongtao Xue, Fuling Tang and Ding Fan Eur. Phys. J. D, 74 12 (2020) 231 Published online: 01 December 2020 DOI: 10.1140/epjd/e2020-10389-7