Three perfluorinated ZnII porphyrins were evaluated as n-type sensitizers in photoelectrosynthetic cells for HBr and water splitting. All the dyes are featured by the presence of pentafluorophenyl electron withdrawing groups to increase the ground state oxidation potential and differ for the nature and the position of the π-conjugate linker between the core and the anchoring group tasked to bind the metal oxide, in order to assess the best way of coupling with the semiconductor. A phenyl-triazole moiety was used to link the carboxylic anchoring group onto meso position, while an ethynyl-phenyl linker was chosen to bridge carboxylic and cyanoacrylic groups onto β-pyrrolic position. A combination of electrochemical, computational and spectroscopic investigations confirmed the strong electron withdrawing effect of the perfluorinated porphyrin core which assures all the investigated dyes of the high oxidation potential required to the coupling with water oxidation catalysts (WOC). Such an electron-poor core, however, affects the charge separation character of the dyes, as demonstrated by the spatial distribution of the excited states, leading to a non-quantitative charge injection, although tilting of the molecules on the semiconductor surface could bring the porphyrin ring closer to the semiconductor, offering additional charge-transfer pathways. Indeed all the dyes demonstrated successful in the splitting of both aqueous HBr and water, with the best results found for the SnO2/TiO2 photoanode sensitized with the β-substituted porphyrin equipped with a cyanoacrylic terminal group, achieving 0.4 and 0.1 mA/cm2 photoanodic currents in HBr and water, respectively, under visible light. The faradaic yield for oxygen evolution in the presence of an IrIV catalyst was over 95% and the photoanode operation stable for more than 1000 seconds. Thus the perfluorinated porphyrins with a cyanoacrylic anchoring group at the β-position should be considered for further development to improve the charge transfer character.