Supported Mn3O4 Nanosystems for Hydrogen Production through Ethanol Photoreforming

Photoreforming promoted by metal oxide nanophotocatalystsis an attractive route for clean and sustainable hydrogengeneration. In the present work, we propose for the first time the useof supported Mn3O4 nanosystems, both pure and functionalized with Aunanoparticles (NPs), for hydrogen generation by photoreforming. Thetarget oxide systems, prepared by chemical vapor deposition (CVD) anddecorated with gold NPs by radio frequency (RF) sputtering, weresubjected to a thorough chemico-physical characterization and utilizedfor a proof-of-concept H2 generation in aqueous ethanolic solutionsunder simulated solar illumination. Pure Mn3O4 nanosystems yielded aconstant hydrogen production rate of 10 mmol h-1 m-2 even forirradiation times up to 20 h. The introduction of Au NPs yielded asignificant enhancement in photocatalytic activity, which decreased as afunction of irradiation time. The main phenomena causing the Aucontainingphotocatalyst deactivation have been investigated by morphological and compositional analysis, providing importantinsights for the design of Mn3O4-based photocatalysts with improved performances.