esearchers at Empa’s Laboratory for High Performance Ceramics (LHPC) in Switzerland have been investigating nanoparticles of metal oxides, such as titanium dioxide (TiO2), for the neutralization of organic pollutants in air and water.
Collaborating with colleagues at the University of Basel and at Argonne National Laboratory in the US, they have now succeeded in making a nano-bio PEC electrode, consisting of iron oxide conjugated with a protein from blue-green algae, which is twice as efficient in water splitting as iron oxide alone.
“I was inspired by the natural photosynthetic machinery of cyanobacteria where phycocyanin acts as a major light-harvesting component. I wanted to make artificial photosynthesis using ceramics and proteins,” said Debajeet K. Bora, who designed the new electrode during his PhD thesis at Empa. “The concept of hematite surface functionalization with proteins was completely novel in PEC research.”
After Bora covalently cross-coupled phycocyanin to hematite nanoparticles that had been immobilized as a thin film, the conjugated hematite absorbed many more photons than without the algal protein. In fact, the induced photocurrent of the hybrid electrode was doubled compared to a “normal” iron oxide electrode.
The project was funded by the Swiss Federal Office of Energy (SFOE). Bora who will soon have completed his PhD thesis says he will continue what he started at Empa during a postdoc at the University of California, Berkeley, which he will assume early this year.