Sintesi e caratterizzazione del fotocatalizzatore Pd/TiO2 per la produzione sostenibile di idrogeno

The main objective of this thesis work is the characterization of three novel semiconductor-based photocatalysts for the green production of solar fuels, as hydrogen, from water. In particular, the support material used was TiO2 P25, on which palladium nanoparticles have been deposited. The coupling of these two systems is exploited to enhance the photocatalytic activity towards the hydrogen evolution reaction. One of the samples investigated, denoted as Photo-Pd (1h), was synthesized using the photodeposition method in our research laboratories, as part of this work. Meanwhile, the other two samples, denoted as Pd-TiO2 (NR) and Pd-TiO2 (R), were produced by Chimet S.p.A., following the deposition precipitation method. The aim of the study is to disclose the synthesis-properties-activity relationships for the three materials to obtain design rules to produce more efficient photocatalysts. Field Emission Scanning Electron microscopy (FESEM) and Transmission Electron Microscopy (TEM) imaging techniques were employed for the study of structure, morphology, particle size and distribution of the supported palladium nanoparticles (NPs). Moreover, the exposed surface sites were probed by FT-IR spectroscopy of adsorbed CO using different activation treatments. Finally, the photocatalytic performance of the three materials was evaluated by following the hydrogen evolution reaction under UV light irradiation carried out in a homemade experimental reactor. The gas evolution was followed with a gas chromatography system connected to the reactor.