New research led by ECS Fellow John Turner, researcher at the National Renewable Energy Laboratory, demonstrates a pioneering, efficient way to make renewable hydrogen.
Hydrogen has many highly sought after qualities when he comes to clean energy sources. It is a simple element, high in energy, and produces almost zero pollution when burned. However, while hydrogen is one of the most plentiful elements in the universe, it doesn’t occur naturally as a gas – instead, it’s always combined with other elements. That’s where efforts in water-splitting come in.
If researchers can effectively split water molecules into oxygen and hydrogen, new branches of hydrogen production could emerge.
Turner and his team are working on a method to boost the longevity of highly efficient photochatodes in photoelectrochemical water-splitting devices.
“Electrochemistry nowadays is really the key,” Turner told ECS during a podcast in 2015. “We have fuel cells, we have electrolyzers, and we have batteries. All of the things going on in transportation and storage, it all comes down to electrochemical energy conversion.”
Photoelectrochemical (PEC) devices could provide an efficient, sustainable way to produce hydrogen. The PEC cell can absorb sunlight and transform that energy into hydrogen and oxygen via the splitting of water molecules.
Turner is working to create a more durable cells to combat issues in the field relating to degradation.
This from NREL:
The concept of using an integrated tandem cell based on the NREL high-efficiency tandem solar cell to split water and produce hydrogen was developed 18 years ago by research fellow Turner, who has been with the laboratory since 1979. He designed a tandem solar cell containing layers of gallium indium phosphide (GaInP2) and gallium arsenide (GaAs) semiconductors to absorb the sunlight and produce the power necessary for the photoelectrochemical water-splitting reaction. Turner’s device held the record for the highest solar-to-hydrogen efficiency, until it was finally eclipsed in 2015.
[The paper shows how] researchers determined that greater photocathode stability and high catalytic activity can be achieved by depositing and annealing a bilayer of amorphous titanium dioxide (TiOx) and molybdenum sulfide (MoSx) onto GaInP2. During a 20-hour durability test, the photocathode retained 80 percent of the initial electricity generated. The TiOx and MoSx produced a catalyst protection layer and served to protect the GaInP2 from the acidic solution.
