Improving the plasmonic efficiency of the Au nanorod-semiconductor photocatalysis toward water reduction by constructing a unique hot-dog nanostructure

Abstract

A novel hot-dog (HD) structured Au NR@Cu2O NPs was designed and synthesized using Au nanorod (NR) as inner “sausage” and Cu2O as outside “bread” to improve the plasmonic efficiency of Au NR so as to enhance their performance of the photocatalysts in water photo reduction reaction. In this unique structure, the head-exposed Au NR provided plasmonic enhanced local electric field at surface of photocatalyst to improve the transfer of electrons. Compared with the traditional photocatalysts composed of bare semiconductors or the metal-semiconductor composite photocatalysts with core-shell (CS) structure, the HD Au NR@Cu2O NPs not only exhibit an extended absorption in visible light wavelength range, but also effectively reduce the recombination rate of photogenerated charge-carriers due to the exposed tips of Au NRs, thus bringing about the significant improvement in H2 production yield. Moreover, the TiO2 shell can be facilely covered on the surface of Au NR@Cu2O to form p-n junction with Cu2O shell to further enhance the efficiency of H2 evolution.