Oz Research Takes Steps Toward Hydrogen Production

In a significant advance for the emerging hydrogen-powered vehicle sector, Australian researchers replicate for the first time one of the crucial steps in photosynthesis, the process of converting light energy to chemical energy.

The Australian National University says the finding opens the way for the development of biological systems powered by sunlight that could manufacture hydrogen as a fuel.

Hydrogen offers potential as a zero-carbon replacement for petroleum products, but until now the way plants produce hydrogen by splitting water has been poorly understood.

“Water is abundant and so is sunlight,” ANU researcher Kastoori Hingorani says in a news release. “It is an exciting prospect to use them to create hydrogen, and do it cheaply and safely.”

Hingorani leads a team at the Australian Research Council’s Center of Excellence for Translational Photosynthesis in the ANU Research School of Biology that created a protein which, when exposed to light, displays the electrical heartbeat that is the key to photosynthesis.

The system uses a naturally occurring protein and does not need batteries or expensive metals, meaning it could be affordable in developing countries, she says.

The team modified a much-researched and ubiquitous protein, Ferritin, which is found in almost all living organisms. Ferritin’s usual role is to store iron, but the team removed the iron and replaced it with the abundant metal manganese to closely resemble the water-splitting site in photosynthesis.

The protein also binds a haem group – a complex red organic pigment containing iron and other atoms to which oxygen binds – which the researchers replaced with a light-sensitive pigment, zinc chlorin. When the researchers shone light onto the modified ferritin, there was a clear indication of charge transfer as in natural photosynthesis.

Co-researcher Ron Pace says the breakthrough opens new possibilities for manufacturing hydrogen as a cheap and clean source of fuel.

“This is the first time we have replicated the primary capture of energy from sunlight,” Pace says. “It’s the beginning of a whole suite of possibilities, such as creating a highly efficient fuel, or to trapping atmospheric carbon.”

Pace says large amounts of hydrogen fuel produced by artificial photosynthesis could transform the economy, as the carbon-free cycle essentially is indefinitely sustainable.

“Sunlight is extraordinarily abundant, water is everywhere – the raw materials we need to make the fuel,” he says. “And at the end of the usage cycle it goes back to water.”