Pokrok v materiálech pro solární štěpení vody
Highly active very thin (< 50 nm) hematite photoanode employed for solar photoelectrochemical water slitting.[/caption] The study recently published in Applied Catalysis B - Environmental (Appl. Catal B-Environ 165, 344 (2015)) as a joint research paper between the groups from University of Nurnberg – Erlangen (Germany), University of Nebraska – Linclon (USA), and RCPTM deals with a significant improvement of photoelectrochemical activity of very thin films of iron oxide in hematite crystalline structure working as the photoanodes. The films were deposited by an advanced plasmatic system known as High Impulse Power Magnetron Sputtering (HiPIMS). It was shown that deposition of very thin (below 50 nm) nanocrystalline hematite films effectively suppressed the negative effect of a short diffusion length of photogenerated holes. Moreover, the photoactivity of hematite was even more enhanced by deposition of ultra-thin (below 2 nm) films of isocrystalline alumina oxide overlayers. In this way the backward recombination of photogenerated electrons and holes was extraordinarily reduced due to the passivation of undesirable surface states acting as traps.