Tech Briefs Magazine - August 2022 - 46

Sustainable Technology
Over a range of 1,900 °C to 2,400 °C, the
new TPV cell maintained an efficiency of
around 40 percent.
The cell in the experiments is about a
square centimeter. For a grid-scale thermal
battery system, Henry envisions the TPV
cells would have to scale up to about
10,000 square feet (about a quarter of a
football field), and would operate in climate-controlled
warehouses to draw power
from huge banks of stored solar energy.
With the new TPV cell, the team has
now successfully demonstrated the main
parts of the system in separate, smallscale
experiments. They are working to
integrate the parts to demonstrate a fully
operational system. From there, they
hope to scale up the system to replace
fossil-fuel-driven power plants and enable
a fully decarbonized power grid,
supplied entirely by renewable energy.
For more information, contact Sarah
McDonnell at s_mcd@mit.edu; 617-2538923.
New
Screening System May Point the Way to Renewable
Hydrogen Power
A highly sensitive system for detecting the production of hydrogen gas can foster the development
of hydrogen as an alternative to fossil fuels.
The Pennsylvania State University, University Park, PA
A
new system for detecting the production
of hydrogen gas, developed by
Penn State researchers, may play a key role
in the quest to develop hydrogen as an environmentally
friendly and economical alternative
to fossil fuels.
" We have built a new system for detecting
hydrogen evolution that is the most
sensitive in the world, " said Professor Venkatraman
Gopalan. " This tackles a problem
that had not been addressed but that is
important going forward for materials discovery. "
The
tool can be used to screen promising
photocatalysts,
materials
that when
placed in water and exposed to sunlight
facilitate reactions that split water molecules
into hydrogen and oxygen gases. The
process, called water splitting, offers a clean
and renewable source of hydrogen, but it is
inefficient, and finding the right photocatalysts
to boost hydrogen production has
been challenging.
In a study, the team found they could test
smaller amounts of photocatalyst material
than previously possible and detect very
small amounts of hydrogen gas produced,
or hydrogen evolution, in the range of tens
of nanomoles per hour per tens of milligrams
of material. They recently published
their findings in the Review of Scientific Instruments.
" If
you ranked low in both the categories
of hydrogen evolution rate and the mass of
the photocatalyst needed, it means it's a really
sensitive system for discovering new
photocatalytic materials, " said Huaiyu
" Hugo " Wang, a graduate student who led
the study and built the system. " And it turns
out that our work ranked the best in both
categories. "
At Penn State, scientists led by Professor
Ismaila Dabo recently used a supercomput46
0.01
[19]
0.001
0.001
0.01
0.1
Detected
H2 rate (µmol/hour)
This chart shows the system's performance at measuring small amounts of material and detecting
development of hydrogen gas. (Image: Penn State)
er to narrow a list of more than 70,000 different
compounds down to six promising
candidates. Another team led by Raymond
Schaak, DuPont Professor of Materials
Chemistry, synthesized the materials in
their laboratory.
However, typical photocatalysts use rare
and precious metals such as platinum,
which are immensely expensive, so making
them in large quantities is impractical,
time-consuming, and costly.
When it came time to test samples, the
researchers found commercial equipment
was not sensitive enough, so Gopalan
and Wang built their own. Gopalan
said their new system will allow scientists
to test smaller amounts of these materiwww.techbriefs.com
als
and focus efforts on the most promising
candidates.
Unlike the commercial units, the new
design can test photocatalysts in their bare
state, the scientists said. To be effective,
photocatalysts require co-catalysts and other
techniques that further improve their
efficiency. The gold standard, for example,
is titanium dioxide with platinum particles
added as a co-catalyst. Photocatalysts without
these add-ons are considered bare.
" When we are looking at new materials,
we don't know what the correct
co-catalysts will be, " Wang said. " Detecting
the bare form is the quickest way to
help guide the direction of this materials
discovery process. "
Tech Briefs, August 2022
1
10
[32]
1
[34] [37] [36]
[31]
0.1
This Work
[35]
[33]
Catalyst Mass(g)

http://www.techbriefs.com

Tech Briefs Magazine - August 2022

Table of Contents for the Digital Edition of Tech Briefs Magazine - August 2022