Direct photocatalytic hydrogen evolution from water splitting using nanostructures of hydrate organic small molecule as photocatalysts

摘要

Organic small molecules with a suitable energy level have usually been considered as photosensitizers rather than catalysts for photocatalytic hydrogen evolution (PHE). Herein, we achieved direct PHE using hydrate zinc tetraphenylporphyrin (ZnP, ZnTPP center dot H2O) nanostructures synthesized by a liquid-phase chemical reaction as photocatalysts. The shape-dependent photocatalysis revealed that the ZnP nanosheets (ZnP-NS) exhibit higher PHE activity (similar to 0.16 mmol g(-1) h(-1)) than the ZnP octahedron nanoparticles (ZnP-NPs) (similar to 0.06 mmol g(-1) h(-1)). After in situ construction of the rubrene/ZnP-NS heterostructure, more efficient PHE of this pure organic nanostructure was obtained due to the occurrence of photoinduced electron transfer and Forster resonance energy transfer (FRET). The optimal PHE rate is similar to 0.56 mmol g(-1) h(-1). Furthermore, with the addition of 3.0 mM methyl viologen (MV) and 3.8 wt% platinum, a PHE rate of similar to 9.3 mmol g(-1) h(-1) can be achieved at pH = 7. This study offers a new route to design organic small molecules as photocatalysts.