"This could be a great platform for developing solar technologies"
The quest to find new ways to harness solar power has taken a step forward after researchers successfully split water into hydrogen and oxygen by altering the photosynthetic machinery in plants.
Photosynthesis is the process plants use to convert sunlight into energy. Oxygen is produced as by-product of photosynthesis when the water absorbed by plants is ‘split’. It is one of the most important reactions on the planet because it is the source of nearly all of the world’s oxygen. Hydrogen which is produced when the water is split could potentially be a green and unlimited source of renewable energy.
A new study, led by academics at St John’s College has used semi-artificial photosynthesis to explore new ways to produce and store solar energy. They used natural sunlight to convert water into hydrogen and oxygen using a mixture of biological components and manmade technologies.
Katarzyna Sokół in the Reisner laboratory in Cambridge. Photo credit: Andreas Wagner
FlynnClubbaire on September 3rd, 2018 at 23:20 UTC »
A big question here is:
How does this compare, in terms of energy recovered, to using a solar panel to perform electrolysis?
IE, what is the ratio of chemical energy stored as hydrogen produced to solar energy input, and is it any better than existing photovoltaic technology?
The answer to that question is probably a resounding no, especially since no claims of such efficiency are made in the abstract, and that would be a pretty huge result.
Frankly, though, the bigger question here is whether or not the theoretical maximum efficiency for this kind of technology exceeds the the theoretical maximum efficiency for photovoltaics.
But ultimately, this technology will only be important if it allows higher profit margins. Frankly, I suspect it will not, given that photovoltaic cells are pretty low maintenance, but specialized chemical solutions (and I mean solution in the chemical sense -- dissolved in water!) are difficult and expensive to maintain.
RedSquirrelFtw on September 3rd, 2018 at 22:47 UTC »
That's really cool, wonder if it would be viable to then burn the hydrogen to power a steam turbine. Or would PV end up being more effective per square meter?
mvea on September 3rd, 2018 at 20:50 UTC »
The title of the post is a copy and paste from the title, first and fifth paragraphs of the linked academic press release here :
Journal References:
Katarzyna P. Sokol, William E. Robinson, Julien Warnan, Nikolay Kornienko, Marc M. Nowaczyk, Adrian Ruff, Jenny Z. Zhang, Erwin Reisner.
Bias-free photoelectrochemical water splitting with photosystem II on a dye-sensitized photoanode wired to hydrogenase.
Nature Energy, 2018;
DOI: 10.1038/s41560-018-0232-y
Link: https://www.nature.com/articles/s41560-018-0232-y
Abstract
Natural photosynthesis stores sunlight in chemical energy carriers, but it has not evolved for the efficient synthesis of fuels, such as H2. Semi-artificial photosynthesis combines the strengths of natural photosynthesis with synthetic chemistry and materials science to develop model systems that overcome nature’s limitations, such as low-yielding metabolic pathways and non-complementary light absorption by photosystems I and II. Here, we report a bias-free semi-artificial tandem platform that wires photosystem II to hydrogenase for overall water splitting. This photoelectrochemical cell integrated the red and blue light-absorber photosystem II with a green light-absorbing diketopyrrolopyrrole dye-sensitized TiO2 photoanode, and so enabled complementary panchromatic solar light absorption. Effective electronic communication at the enzyme–material interface was engineered using an osmium-complex-modified redox polymer on a hierarchically structured TiO2. This system provides a design protocol for bias-free semi-artificial Z schemes in vitro and provides an extended toolbox of biotic and abiotic components to re-engineer photosynthetic pathways.