Enhanced hydrogen storage/sensing of metal hydrides by nanomodification

Abstract

Metals/metal hydrides have attracted much attention for hydrogen storage and sensing owing to their excellent ability to store hydrogen. The nanomodification strategy has a remarkable effect on the improvement of hydrogen storage and sensing properties. Herein, the nanomodification strategy mainly includes nanoconfinement for metal hydrides, nanosized metals/metal hydrides, and nanoadditives for metal hydrides. We first review the properties of metal hydrides and summarize the research process of nanosized metal hydrides and nanoadditives for metal hydrides in the recent five years. The synthesis methods of preparing nanometal hydrides are outlined, which includes the bottom-up and top-bottom strategy. Notably, the effort of the nanoconfinement, which limits the growth and the aggregation of metal hydride particles, is presented with detailed introduction of many different kinds of host materials, including carbons, metal-organic frameworks, porous metals, porous metal oxides, and so on. The effect on the enhanced hydrogen storage performance by nanosized metal hydrides is emphasized. In addition, we sum up the research studies about various kinds of nanoadditive doping into metal hydride systems, such as metals and intermetallic compounds, metal oxides and sulfides, metal fluorides, and so on. We study and highlight the influence of metal hydrides doped with nanoadditives with improved kinetics for hydrogen storage. Besides, we also investigate the hydrogen sensing property of nanostructured noble metals, as well as the process of metal hydride formation. Future research directions and perspectives are also being discussed for the development of hydrogen storage and sensing based on metals/metal hydrides.