Exploration into the Syntheses of Gallium- and Indiumborates under Extreme Conditions: M5 B12 O25 (OH): Structure, Luminescence, and Surprising Photocatalytic Properties.
Daniela VitzthumKlaus WurstJohann M PannPeter BrüggellerMarkus SeibaldHubert HuppertzPublished in: Angewandte Chemie (International ed. in English) (2018)
Explorative solid-state chemistry led to the discovery of the two new compounds Ga5 B12 O25 (OH) and In5 B12 O25 (OH). Extreme synthetic conditions within the range of 12 GPa and a temperature of 1450 °C realized in a Walker-type multianvil apparatus resulted in the formation of an unprecedented tetragonal structure with the exclusive presence of condensed BO4 tetrahedra, forming cuboctahedral cavities. Doping of these cavities with Eu3+ in In5 B12 O25 (OH) yielded in an orange-red luminescence. Photocatalytic tests of In5 B12 O25 (OH) revealed a hydrogen production rate comparable to TiO2 but completely co-catalyst free.