Using sunlight to split water

Scientists from the University of Wollongong (UOW) are behind the establishment of a global consortium which is using sunlight to convert water into important chemical fuels such as hydrogen gas.

The research promises a significant reduction of greenhouse gas emissions by reducing CO₂ from fossil fuel use. The process would also have commercial benefits, as it would be a renewable and low-cost fuel option.

Leading research scientists from the USA (Rutgers and Princeton Universities) and Germany (University of Stuttgart) have been visiting Wollongong in an important step towards establishing a global research consortium to develop effective strategies for water splitting. Scientists from India (Tata Institute of Fundamental Research and the Indian Institute of Science) will also engage in the global project.

The consortium, being driven by researchers from the UOW’s ARC Centre of Excellence for Electromaterials Science (ACES), is bringing together the skills necessary for the project - including the design of molecular catalysts, fabrication of nanostructured electrodes, cell design and practical implementation.

“Advances in our understanding of nature’s catalytic principles coupled with advances in nanofabrication bring us ever closer to a truly sustainable energy future - but the challenge in delivering practical systems that can be economically implemented remains formidable,” ACES Executive Director, Professor Gordon Wallace, said.

“It is envisaged that the global consortium will make significant strides forward bringing together synergies that will provide more effective progress through an integrated team approach.

“A global team is essential to tackling complex research challenges that will have an international impact and water splitting is certainly one of those. It makes sense to bring together the best minds on the planet if we are going to progress in a reasonable time frame.”

The UOW team behind recent developments consists of Professor Gerry Swiegers, Professor David Officer and Professor Wallace. The core technology comprises separate but complementary innovations developed via collaborations between UOW, Princeton University, Rutgers University and Monash University.

Professor Wallace said these innovations can now be packaged together to provide an efficient method of splitting water into its component parts using only sunlight.

Broadly, the technologies involve the use of novel catalytic processes that enhance the efficient production of certain molecules of interest.

Professor Wallace said the first technology uses a highly-efficient chemical process, via novel electrocatalysts, to convert water into hydrogen gas.

The second technology mimics the water-oxidising centre in photosynthesis to produce oxygen gas from water under sunlight (ie, splitting of water to form oxygen). Fully functional mimicry of this type has not previously been achieved.

“Put together, these technologies offer a cutting-edge advance for the splitting of water into its component parts, hydrogen and oxygen, as well as the reverse process - the production of an electrical current from the combination of the elemental hydrogen and oxygen to form water.

“The combination of these technologies offers a means of efficiently creating hydrogen gas (as a fuel) and then converting it into a powerful electric current by using it in an H₂/O₂ fuel cell.

“The water-splitting application has been demonstrated in simple ‘proof of concept’ devices within the laboratory.

“The research teams are currently performing studies to obtain efficiency data and are working towards engineering a prototype device. The ultimate aim is to develop commercial devices able to spontaneously convert water into hydrogen and oxygen under sunlight.”