Valérie KELLER
University of Strasbourg
France
Title: Synthesis and reactivity of Au/g-C3N4/TiO2 nanocomposites for water-splitting and H2 production under solar light illumination
Biography
Biography: Valérie KELLER
Abstract
Nowadays, the major challenge is to find new environmentally friendly ways to produce energy that may cover the global consumption. The direct conversion of solar energy though an energy carrier (fuel), storable and usable upon request, appears as an interesting alternative. Photocatalysis is an innovative and promising way to produce pure hydrogen from renewable energy sources. Indeed, the water dissociation (water-splitting) highlighted by Fujishima and Honda in a photoelectrocatalytic cell opened a promising way to produce hydrogen from light energy. In our study, we will focus on a photocatalytic TiO2-based system associated with graphitic carbon nitride (g-C3N4). With a band gap of 2.7 eV, g-C3N4 allows the valorization of an important part of the visible light spectra in the context of water splitting. TiO2 powder is obtained via a “sol-gel” process and g-C3N4 was obtained via a thermal polycondensation reaction of specific nitrogen-containing precursors. g-C3N4/TiO2 nanocomposites were obtained either (i) by introducing g-C3N4 (as synthesized) during the sol-gel synthesis of TiO2 or (ii) by introducing TiO2 (as synthetized) during the g-C3N4 synthesis. Gold nanoparticles were synthesized - directly onto the TiO2, the g-C3N4 and the g-C3N4/TiO2 support – by chemical reduction of the HAuCl4 precursor in an excess of NaBH4. The synthesis of new nanostructured composites allowed us to achieve better hydrogen production yield than the reference Au/TiO2 and Au/g-C3N4 samples. Future goals are to find the optimal amount of Au on the Au/g-C3N4/TiO2 composites but also the optimal amount of g-C3N4.