A breakthrough method uses solar energy to produce green hydrogen from water

Is there anything that the mighty Sun can’t do?

Rupendra Brahambhatt
A breakthrough method uses solar energy to produce green hydrogen from water
Nanotechnology and abstract graphene structures.Olemedia/iStock

A team of researchers at the University of Strathclyde has claimed that solar energy can be utilized for large-scale hydrogen energy production. Although hydrogen is one of the cleanest sources of energy, even today, most of the hydrogen we produce still comes from fossil fuels. A shocking report from the US Department of Energy reveals that natural gas plants are sources of 95 percent of the hydrogen produced in the country.

As a result of these fossil-fuel-driven hydrogen production methods, greenhouse gases in large amounts are released into the atmosphere. These gases worsen the climate change crisis that our planet is currently going through. However, this can be prevented if we discover a green and sustainable way to produce hydrogen. 

The scientists at the University of Strathclyde have proposed one such method in their recent study published in Angewandte Chemie, a science journal run by the German Chemical Society. 

The practical approach to green hydrogen fuel production

Splitting of a water molecule in the presence of Iridium. Source: Angewandte Chemie International Edition

The production of green hydrogen from water requires a material that could trigger the breakdown of water into hydrogen and oxygen using light. Such material is called a photocatalyst. Scientists have been using sacrificial electron donors for hydrogen production in many previous experiments.

Although these agents could increase hydrogen yield by lowering the recombination tendency of electrons and holes, they couldn’t be employed for large-scale hydrogen fuel generation. The researcher at the University of Strathclyde claims that storable hydrogen can be produced in large quantities by performing photocatalysis of water in the presence of sunlight using a particulate conjugated polymer containing a metal catalyst as iridium.

When asked about the significance of the conjugate polymer, Principal researcher Sebastian Sprick told Interesting Engineering, “Conjugated polymers (loaded with material like Iridium) have significant potential due to their tunability by chemical synthesis allowing for better materials design in the future.” However, since Iridium is a rare material, Sprick further adds, “research will focus now on replacing these rare metal catalysts to allow for scale-up of materials to tackle hydrogen production at scale efficiently.”

Some previous studies have confirmed that the biggest challenge in green hydrogen production is to ensure the availability of a vast renewable power source. As solar power is both an easily accessible and renewable source of energy, and it is available in an abundant amount on Earth. Sprick and his team of researchers reveal that photocatalytic splitting of water under the influence of sunlight can prove to be the most efficient and cleanest way to produce green hydrogen on a large scale. 

For instance, the amount of solar energy that reaches Earth in an hour is more than enough to meet the global power demands for an entire year. A research paper published last year in Nature also highlights that solar energy-backed photocatalysis is a highly efficient and budget-friendly technique to produce hydrogen. 

According to Sprick, “the reported photocatalyst can access solar energy through energetically unfavorable processes to generate a storable energy carrier in the form of hydrogen from water. The hydrogen then can be converted cleanly into electricity in a fuel cell with water being the only side-product.”

Is green hydrogen the future?

Hydrogen produced through solar photocatalysis using conjugate polymer does not lead to carbon emissions. Plus, no greenhouse gases are released when this hydrogen is turned into a hydrogen fuel cell. Therefore, almost clean and green hydrogen production can be achieved using this method.

A report from International Energy Agency, green hydrogen has excellent potential as it can significantly decrease our dependence on fossil fuels and lower the global carbon footprint. Industries such as shipping, petroleum refining, transportation, and aerospace that currently create a lot of pollution due to traditional fuels can become nearly pollution-free by using gree hydrogen. 

Last year the UK government announced that by 2030 they aim to produce enough hydrogen fuel to meet the energy demand of three million households. The country’s national grid is also developing a hydrogen-based network to produce clean electricity. The French government is making enormous investments to increase its green hydrogen production. A market report reveals that France will invest $7.28 billion (7 billion euros) by the end of this decade to achieve its green hydrogen goals.