Active phase of metal-doped C3N4 ultrananosheets for photocatalytic H2 production.

H2 has been recognized as a promising renewable energy vector. Methanol is a desired candidate as sacrificial agent for photocatalytic H2 production, because of its high H content and its availability from a wide range of renewable processes, covering biomasses valorization and CO2 reduction. A serie of metal-doped single atoms C3N4 ultrananosheets (SA-UNS) materials has been tested for photocatalytic dehydrogenation of methanol, observing different performance depending on the chemical nature of metal (Pt and Pd) and its loading (0.3 - 1.0 wt%). For this proposal, the high specificity of XAS technique will be exploited to reveal the structure of the representative M(SA)/UNS after irradiation during photocatalytic dehydrogenation of methanol. We expect to highlight the nature of the metal dopants, discriminating between the formation of single atoms or metal nanoparticles. Important will be elucidating the evolution of the metal active phase with irradiation time, to be related with the photocatalytic performance observed. The information regarding chemical state and local structure around the metal dopants will be crucial to understand the working mechanism of the materials and will help in design of photocatalysts with improved performance.