The SNON project focuses on synthesis of new nanostructured metal oxy nitride photocatalytic materias for hydrogen production by photo-electrolysis of water under sun light. The project will explore a class of materials based on tantalum, titanium and zinc oxy-nitrides (from Ta2O5 to Ta3N5, and ZnON, TiON) with different micro- and nano-structures, from nanoparticles to the ultra-thin and nanopatterned films. The main interest is to obtain a decrease of the energy band gap while keeping a low recombination rate of photoelectrons and photoholes in order to enhance the photocatalytic activity of these materias in visible light range.
The SNON project will use plasma assisted depositions, pulsed laser depositions, and nanopatterning techniques to fabricate nanostructured materials with high photocatalytic activity in visible light. A variety of methods will be used to achieve this goal:1) deposition of metal oxy nitrides thin films with low energy gap (< 2 eV) and low defect density; 2) use of particulate, nanoclastered and nanopatterned thin films to confine the photo excited charge carriers at surface and to increase the specific active surface; 3) use of rough substrates to increase the specific active area; 4) use of cocatalyst particulate metals for electron trapping; 5) use of transparent conductive substrates as photocatalytic electrodes for a better collection of charge carriers.
Synthesis of the particulate, nanoclastered and nanopatterned metal oxynitrides thin films and transparent electrodes will be subject of cooperation work between research groups from IPARC (Iasi Plasma Advanced Center) of Alexandru Ioan Cuza University (UAIC) (Iasi, Romania) LPGP (Laboratoire des Physique des Gaz et des Plasmas) (Universite Paris Sud, Orsey, France) and and LEDNA (Laboratoire Edifices Nanometriques), IRAMIS-CEA (Saclay France), respectively. Characterization and testing of structured materials in solar photocatalytic cell for hydrogen production will be performed by French partners at LISO (Laboratoare des Interfaces est Surfaces d’oxydes) IRAMIS-CEA (Saclay, France) and SCM (Semiconducteurs en Couches Minces) at LGEP-Supélec (Gif sur Yvette, France). This research consortium takes advantage of particular expertise of each research group, which is increasing the potential of project to produce a demonstration of principle of an efficient visible light photoelectrochemical cell. Scientifically, the project will give an insight on the effect of nanostructuring of photocatalytic materials on the photocatalytic activity. Also, the project will explore the potential of high impulse magnetron sputtering and pulsed laser depositions for synthesis of high quality photocatalytic metal oxy-nitride ultra-thin films, included clustered and nanoparticulate thin films. Moreover, the project will investigate the use of the plasma and laser deposition techniques in combination with the colloidal lithography.
The SNON project will build a cooperation platform for research groups from Romania and France, which could last beyond the project end. This cooperation project will offer the chance for young researchers (master and doctoral students) to learn and work in international environment and to cooperate in fulfilling various project tasks. The project foresees joint meetings and a common workshop, events that will create opportunities for true scientific communication and advancement in this particular research and technological field.