Newly discovered nanoscale “cubes” found to be efficient catalysts
Researchers at Tokyo Metropolitan University created sheets of transition metal chalcogenide “cubes” connected by chlorine atoms. Unlike previous studies on atom sheets like graphene, this team used clusters instead, which breaks new ground. The research was published in the journal Advanced Materials.
The team successfully formed nanoribbons inside carbon nanotubes for structural characterization and microscale sheets of cubes that could be exfoliated and probed. These sheets were shown to be an excellent catalyst for generating hydrogen.
Two-dimensional materials have unique electronic and physical properties due to their sheet-like nature. While graphene is well known, there has also been a focus on transition metal chalcogenides (TMCs), which are composed of a transition metal and a group 16 element like sulfur or selenium.
The researchers were inspired to try a different approach: using TMC clusters instead of atoms to form two-dimensional patterns. This new route would yield a whole different class of nanomaterials.
The team focused on cubic “superatomic” clusters of molybdenum and sulfur, growing their material from a vapor of molybdenum (V) chloride and sulfur in the nanoscale confines of carbon nanotubes.
They found that the material consisted of isolated molybdenum sulfide “cubes” connected by chlorine atoms, distinct from cubic structures found in bulk materials. They also discovered microscale flakes composed of the same superatomic clusters arranged in a hexagonal pattern coating the inside of their glass reaction tube.
The team showed theoretically that the same structure under tiny stresses could emit light and might be an effective catalyst for generating hydrogen. Compared with molybdenum disulfide, the new layered material showed significantly higher current at lower voltages when probed, indicating greater efficiency.
Their new approach to assembling nanosheets promises a whole range of new rationally designed materials with exciting new functions.
Source: https://phys.org/news/2024-07-newly-sheets-nanoscale-cubes-efficient.html