Efficient solar hydrogen production of zinc trimesityl porphyrin-based photocatalysts

Dye-sensitized photocatalytic systems (DSPs) have emerged as a promising strategy to achieve efficient and stable solar-driven H-2 evolution systems. In this work, we prepared and tested a series of zinc-trimesityl porphyrin carboxylic acid derivatives as photosensitizes in DSPs for H-2 evolution. In order to unveil the influence of the anchoring group, different positions of the carboxylic acid were studied. All porphyrins were adsorbed onto platinum-doped titanium dioxide nanoparticles (Pt-TiO2 NPs) and were irradiated by a white LED source. The DSPs coated with Zn-TM(pCOOH)P(i.e. the carboxylic acid at the para-phenyl position) illustrated increased stability (2514 TONs for 1.0 x 10(-5) M) and the highest H-2 evolution activity (1959 mmol g(-1) h(-1) for 1.5 x 10(-4) M). These results reveal that efficient and stable DSPs for H-2 evolution can be developed by utilizing porphyrin derivatives as photosensitizers.