Insight into Cd0.9Zn0.1S solid-solution nanotetrapods: Growth mechanism and their application for photocatalytic hydrogen production

Shape-controlled synthesis of semiconductor nanocrystals enables fine manipulation over their physicochemical properties. In this paper, unique Cd0.9Zn0.1S tetrapod nanostructures consisting of two different polymorphisms, i.e., wurtzite and zinc blende, were successfully synthesized via a simple ethylenediamine-assisted solvothermal route. It is found that the temperature determines the formation of the zinc blende-structured seeds, while the ethylenediamine facilitates the subsequent preferential growth of the wurtzite phase arms. Furthermore, the tetrapods, characterized by a type-II staggered band alignment, have shown enhanced photocatalytic performance for H2 generation from an aqueous solution containing electron donors under visible light irradiation, in comparison to the nanocrystals with distinct morphologies. Our results indicate that coupling different polymorphisms in a nanocrystal may be advantageous for photocatalytic proton reduction over single-crystal photocatalyst.