Lithium doping on covalent organic framework-320 for enhancing hydrogen storage at ambient temperature

Fig. 1. The optimized cluster model used here to represent the COF-320 and possible adsorption sites (A, B, C) for adsorption of metals in the COF-320. The dangling bonds are terminated by H atoms. C, H, and N atoms are shown as gray, white, and blue colors, respectively. Fig. 2. The adsorption isotherm of H2 in the pristine and Li-doped COF-320 at 298 K.