The role of dissolution in the synthesis of high-activity organic nanocatalysts in a wet chemical reaction

Abstract

The synthesis of high-activity nanocrystals (NCs) is a key factor in the field of nanocatalysis. By combining nucleation/growth with the dissolution of crystals in a reaction–diffusion system for the first time, we achieved a simple strategy for the one-step synthesis of high-activity uniform nanocatalysts without capping agents (CAs) via simply adjusting the reaction time of the wet chemical reaction (WCR). In this work, the shape evolution of hydrate tetraphenyl-porphyrin zinc (ZnTPP·H₂O, ZnP) NCs was systematically studied during the reaction of their precursor with water. Regular, thermodynamic octahedral ZnP NCs can be synthesized at the 3^rd hour, and typical rough step-type cuboctahedron NCs can be obtained after 3 days due to the occurrence of chemical dissolution in the multistep WCR. Our results reveal that the crystal dissolution process involves the disappearance of low-energy facets followed by the appearance of high-energy facets. Furthermore, ZnP/rubrene heterojunctions can be easily prepared based on the rough NCs. Compared with regular octahedral ZnP NCs and even nanosheets with more active {020} facets, the rough and heterostructured ZnP NCs exhibit higher performance in photocatalytic hydrogen evolution (PHE). These findings provide a convenient method to synthesize highly active nanocatalysts in a multistep WCR.