Photoinduced hydrogen release from hydrogen boride sheets.

ABSTRACT: Hydrogen boride nanosheets (HB sheets) are facilely synthesized via ion-exchange treatment on magnesium diboride (MgB₂) in an acetonitrile solution. Optical absorption and fluorescence spectra of HB sheets indicate that their bandgap energy is 2.8?eV. According to first-principles calculations, optical absorption seen at 2.8?eV is assigned to the electron transition between the ?-bonding states of B and H orbitals. In addition, density functional theory (DFT) calculations suggest the other allowed transition from the ?-bonding state of B and H orbitals to the antibonding state with the gap of 3.8?eV. Significant gaseous H₂ release is found to occur only under photoirradiation, which causes the electron transition from the ?-bonding state to the antibonding state even under mild ambient conditions. The amount of H₂ released from the irradiated HB sheets is estimated to be 8?wt%, indicating that the sheets have a high H₂-storage capacity compared with previously reported metal H₂-storage materials.

SUBMITTER: Kawamura R 

PROVIDER: S-EPMC6814783 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature