How To Extract Hydrogen Fuel from Seawater

It’s possible to produce hydrogen to power fuel cells by extracting the gas from seawater, but the electricity required to do it makes the process costly. UCF researcher Yang Yang from the University of Central Florida (UCF)  has come up with a new hybrid nanomaterial that harnesses solar energy and uses it to generate hydrogen from seawater more cheaply and efficiently than current materials. The breakthrough could someday lead to a new source of the clean-burning fuel, ease demand for fossil fuels and boost the economy of Florida, where sunshine and seawater are abundant. Yang, an assistant professor with joint appointments in the University of Central Florida’s NanoScience Technology Center and the Department of Materials Science and Engineering, has been working on solar hydrogen splitting for nearly 10 years.

It’s done using a photocatalyst – a material that spurs a chemical reaction using energy from light. When he began his research, Yang focused on using solar energy to extract hydrogen from purified water. It’s a much more difficulty task with seawater; the photocatalysts needed aren’t durable enough to handle its biomass and corrosive salt.

We’ve opened a new window to splitting real water, not just purified water in a lab,” Yang said. “This really works well in seawater.”

As reported in the journal Energy & Environmental Science, Yang and his research team have developed a new catalyst that’s able to not only harvest a much broader spectrum of light than other materials, but also stand up to the harsh conditions found in seawater.

 

Source: https://today.ucf.edu/

Water To Drink From The Sea

University of Illinois (U. of I.) engineers have found an energy-efficient material for removing salt from seawater that could provide a rebuttal to poet Samuel Taylor Coleridge’s lament, “Water, water, every where, nor any drop to drink.” The material, a nanometer-thick sheet of molybdenum disulfide (MoS2) riddled with tiny holes called nanopores, is specially designed to let high volumes of water through but keep salt and other contaminates out, a process called desalination. In a study published in the journal Nature Communications, the Illinois team modeled various thin-film membranes and found that MoS2 showed the greatest efficiency, filtering through up to 70 percent more water than graphene membranes.

water

Even though we have a lot of water on this planet, there is very little that is drinkable,” said study leader Narayana Aluru, a U. of I. professor ofmechanical science and engineering. “If we could find a low-cost, efficient way to purify sea water, we would be making good strides in solving the water crisis”.
Finding materials for efficient desalination has been a big issue, and I think this work lays the foundation for next-generation materials. These materials are efficient in terms of energy usage and fouling, which are issues that have plagued desalination technology for a long time,” said Aluru, who also is affiliated with the Beckman Institute for Advanced Science and Technology at the U. of I.

Most available desalination technologies rely on a process called reverse osmosis to push seawater through a thin plastic membrane to make fresh water. “Reverse osmosis is a very expensive process,” Aluru said. “It’s very energy intensive. A lot of power is required to do this process, and it’s not very efficient. In addition, the membranes fail because of clogging. So we’d like to make it cheaper and make the membranes more efficient so they don’t fail as often. We also don’t want to have to use a lot of pressure to get a high flow rate of water.

Source: https://news.illinois.edu/