“In rust we trust”. Hematite – the prospective inorganic backbone for artificial photosynthesis

• DOI: 10.1039/c2ee23668k
• Publication Date: 2012-12-04T20:00:16Z
• Authors: Debajeet K. Bora; Artur Braun; Edwin C. Constable
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

The search for affordable high performance electrode materials in photoelectrochemical hydrogen production by solar water splitting is an ongoing quest. Hematite is a photoanode material with an electronic band gap suitable for efficient absorption of visible light in a photoelectrochemical cell (PEC). Although its poor electronic structure makes hematite a controversial candidate for PEC, it remains promising because it is an earth abundant, chemically stable and low cost material – necessary prerequisites for PEC to become a competitive cost-efficient solar fuel economy. In addition to reviewing some recent PEC research on hematite and its relevant physical and chemical characteristics, we show how hematite obtained by a low cost synthesis can be refined by hydrothermal treatment and further functionalized by coating with phycocyanin, a light harvesting protein known for photosynthesis in blue-green algae.