Novel hollow nitrogen-containing carbon spheres have been prepared by a simple CO(2) activation method at 1223 K using the precursor of ordered mesoporous carbon nitrides which were replicated from SBA-15 template. Rich narrow-distributed micropores have been found in the sphere shell. The structural transformation from solid to hollow sphere is correlated with the surface curvature stress and mass transportation. This material exhibits a high hydrogen storage capacity of 2.21 wt.% at room-temperature under 8 MPa. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.