Hydrogen is one of promising energy sources with virtually non-polluting. In this paper, the hydrogenation mechanism and hydrogen storage weight percentage of new forms of CNCs, BNNCs and SiCNCs with an apex angle of 112.9 degrees are investigated for first time using density functional theory (DFT) and applying B3LYP level at 6-31 g(d,p) basis. The calculations underscore that for all nanocones; CNCs, BNNCs and SiCNCs the convex surface is always more energetic favorite for hydrogenation comparing with the concave surface of nanocones. Also, the hydrogen storage weight percentage is always enhanced via cross stacking nanocones. Noticeably, it is found that the electron density is widely distributed up the next neighbor atoms of pentagon ring via cross stacking, however for single nanocones is mostly concentrated on the atoms of the conical part (pentagon ring). Finally, the results show that the best candidate nanocone for hydrogen storage is the cross stacking nanocones. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.