2D Janus materials could harvest abundant hydrogen fuel

Date:
February 23, 2023
Source:
Springer
Summary:
Several studies have predicted that the water splitting reaction
could be catalyzed by certain groups of 2D materials -- each
measuring just a few atoms thick. New calculations present a new
group of four 2D materials whose two sides each feature a different
molecular composition, which could be especially well suited to
the task.


Facebook Twitter Pinterest LinkedIN Email
FULL STORY ========================================================================== Several studies have predicted that the water splitting reaction
could be catalysed by certain groups of 2D materials -- each measuring
just a few atoms thick. One particularly promising group are named 2D
Janus materials, whose two sides each feature a different molecular composition. Through new calculations detailed in EPJ B, Junfeng Ren and colleagues at Shandong Normal University in China present a new group
of four 2D Janus materials, which could be especially well suited to
the task.


========================================================================== Since hydrogen releases an abundance of energy when combusted, with
only water as a by-product, it is now widely seen as an excellent
alternative to fossil fuels. Splitting water molecules involves a
'redox reaction,' where electrons and holes participate in reduction and oxidation reactions. Since they are excellent semiconductors, 2D Janus materials are particularly well suited to catalysing this reaction. When
an electron in a semiconductor's insulating 'valence band' absorbs a
photon, it is excited to the material's 'conduction band,' leaving behind
a positively charged hole. In turn, these materials as both source and acceptors of electrons -- allowing redox reactions to occur more readily.

In their theoretical study, Ren's team examined a group of four of these materials: with one surface composed of either selenium or tellurium, and
the other from either bromine or iodine -- with both sides sandwiching a
middle layer of astatine. In these semiconductors, the energies of their valence and conduction bands were far enough apart to prevent electrons
and holes from readily recombining: allowing them to combine electrons and holes to produce hydrogen and oxygen. With all four materials displaying excellent stability and light absorption, the researchers believe
they could be incredibly promising candidates for catalysing the water splitting reaction. If these results can be reproduced in experiments,
Ren's team hope the four materials could become a key element of the
global effort to eliminate our carbon emissions in the next few decades.

* RELATED_TOPICS
o Matter_&_Energy
# Materials_Science # Civil_Engineering #
Engineering_and_Construction # Nature_of_Water
o Earth_&_Climate
# Water # Renewable_Energy # Drought_Research #
Environmental_Issues
* RELATED_TERMS
o Materials_science o Metallurgy o Mica o Polymer o Hygroscopy
o Nanoparticle o Smoulder o Molecule

========================================================================== Story Source: Materials provided by Springer. Note: Content may be edited
for style and length.


========================================================================== Journal Reference:
1. Jiali Wang, Jiajun Lu, Xiuwen Zhao, Guichao Hu, Xiaobo Yuan,
Junfeng Ren.

Two-dimensional Janus AsXY (X = Se, Te;
Y = Br, I) monolayers for photocatalytic water
splitting.

The European Physical Journal B, 2023; 96 (2) DOI:
10.1140/epjb/s10051- 023-00486-2 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2023/02/230223132906.htm

--- up 51 weeks, 3 days, 10 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)