Microwave Hydrothermal Synthesis of Ni-based Metal–Organic Frameworks and Their Derived Yolk–Shell NiO for Li-Ion Storage and Supported Ammonia Borane for Hydrogen Desorption

This paper reports fast microwave hydrothermal synthesis of Ni-based metal–organic frameworks (Ni-MOFs) and their derived yolk–shell NiO structures by direct calcination in air. The molar ratio of the Ni ion to the benzene-1,3,5-tricarboxylic acid (H3BTC) ligand has important influence on the NiO morphologies and their electrochemical performances. The obtained yolk–shell NiO microsphere displays a large reversible capacity of 1060 mAh g–1 at a small current density of 0.2 A g–1 and a good high-rate capability when evaluated as an anode for rechargeable lithium-ion batteries. Moreover, the facilitated hydrogen release from ammonia borane (AB) at a lower temperature and the depressed release of undesired volatile byproducts are also observed in the Ni-MOFs supported AB.