Enhanced reversible hydrogen storage efficiency of zirconium‐decorated biphenylene monolayer: A computational study

Abstract

AbstractMetal decorated carbon‐containing two‐dimensional monolayers have been explored as potential hydrogen storage materials because of their open structures which improve the storage capacity. Here, the H2 storage capability of the Zr‐decorated biphenylene nanosheet is studied with the aid of first‐principles calculations. Biphenylene is a recently synthesized ultra‐flat material consisting of different‐sized carbon rings. Zr atom interacts strongly with the monolayer with a binding energy of −4.79 eV due to charge transfer from Zr 3d orbital to C‐2p orbital of biphenylene nanosheet. The hydrogen molecules bind to the Zr‐decorated biphenylene monolayer with an average adsorption energy of −0.4 eV per H2 due to Kubas‐type interactions involving charge transfer between metal d orbital and H‐1s orbital. The Zr decoration helps to adsorb up to 9 hydrogen molecules per metal atom on the monolayer resulting in the H2 uptake of 9.95 wt%, higher than the target of 6.5 wt% set by the Department of Energy (DoE), USA. The high diffusion barrier for the Zr atom prevents metal‐metal clustering. The ab initio molecular dynamics (AIMD) simulations show that the complexes remain stable even at the highest desorption temperature. The present study shows that the Zr‐decorated biphenylene can be considered a prospective two‐dimensional material for reversible hydrogen storage.