Hydrogen storage on the Ca-decorated defective boron nitride nanosheets (BNNSs) is investigated by first-principle calculation based on density functional theory. Four types of experimentally available defects, B vacancy (V_B), N vacancy (V_N), Stone-Wales defect (SW) and B–N divacancy (V_NB), are considered. It is found that the binding energy of Ca atom on BNNSs with V_N and SW defects is smaller than the cohesive energy of bulk Ca. While the Ca atom has strong bonding strength with BNNSs with V_B and V_BN defects without the problem of aggregation. Six H₂ molecules can be absorbed by a Ca atom with the average adsorption energy of 0.206–0.242 eV/H₂. The Ca decorated on both sides of BNNSs with V_B and V_BN defects leads to the hydrogen gravimetric density of 7.6 wt% and 8.0 wt%, respectively. Both the polarization mechanism and the weaker hybridization of Ca-3d orbitals with H-s orbitals are responsible for the adsorption of H₂ molecules. The effect of temperature and pressure on the hydrogen storage performance is also investigated, and the results indicate that the hydrogen adsorbed structures of Ca-decorated BNNSs with V_B and V_BN defects are stable at room temperature under mild pressure.

通过基于密度泛函理论的第一性原理研究，研究了钙修饰的氮化硼纳米片（BNNSs）上的氢存储。考虑了四种可用的实验缺陷：B空位（V _B），N空位（V _N），Stone-Wales缺陷（SW）和B–N空位（V _NB）。结果发现，Ca原子在具有V _N和SW缺陷的BNNS上的结合能小于块状Ca的内聚能。Ca原子与具有V _B和V _BN缺陷的BNNS具有很强的键合强度，而没有聚集问题。六个H ₂分子可被Ca原子吸收，平均吸收能为0.206–0.242 eV / H₂。在具有V _B和V _BN缺陷的BNNSs的两面上装饰的Ca导致氢重量密度分别为7.6 wt％和8.0 wt％。极化机制和Ca-3 d轨道与H- s轨道的较弱杂交都与H ₂分子的吸附有关。还研究了温度和压力对储氢性能的影响，结果表明，具有V _B和V _BN缺陷的Ca修饰的BNNS的氢吸附结构在室温和适度压力下是稳定的。