Nanocrystalline Materials for Photoelectrochemical Water Splitting

Climate change and the depletion of fossil fuels are increasing the urgency to develop clean, cheap, and renewable energy sources. Solar water splitting to form molecular hydrogen and oxygen is an ideal strategy to produce clean and recyclable hydrogen as an energy source. In the present work, materials with sufficient abundance and suitable bandgap energies for visible light harvesting such as hematite and pyrite were studied for photoelectrochemical (PEC) and photocatalytic (PC) water splitting. Commercially available and self-prepared crystalline nanoparticles were employed as the photoelectrodes or as the photocatalysts for PEC or PC water splitting, respectively. The electrochemical behavior of prepared photoanodes and photocathodes were investigated in the dark and under visible light irradiation. The photocatalytic production of oxygen over hematite and hydrogen over pyrite was studied in both bare and modified photocatalysts. The surface of the photocatalysts was modified with various co-catalysts including noble metals and metal oxides to enhance their photocatalytic activity.