Since hydrogen is a kind of potential source of efficient and pollution-free energy, it has attracted great research interests in recent years. However, the lack of safe and efficient hydrogen storage materials has blocked the rapid development of hydrogen energy. Here, we explored the possibility of Li-decorated g-C3N4 as a kind of potential hydrogen storage materials based on first-principles calculations. Our results demonstrated that the adsorption energy of Li atoms on g-C3N4 is much larger than the cohesive energy of bulk Li. Importantly, we find that the binding energy of each H-2 molecule is about 0.29 eV, which is quite suitable for hydrogen storage. Furthermore, the estimated hydrogen storage capacity is around 9.2 wt %, which beyonds the goal of DOE. Thus, we predicted that Li -decorated g-C3N4 may act as the potential hydrogen storage materials. (C) 2016 Elsevier B.V. All rights reserved.