Effective electron collection in highly (110)-oriented ZnO porous nanosheet frameworkphotoanode

Abstract

A highly (110)-oriented ZnO porous nanosheet framework is designed as the photoanode inphotoelectrochemical systems, by virtue of its anisotropic electronic properties. It can befacilely prepared in large scale via a hydrothermal method. X-ray diffraction (XRD)analyses show that the orientation index of the (110) diffraction plane is 3.54, indicatingthe films possess (110) preferred orientation. Field-emission scanning electron microscope(FE-SEM) images exhibit that most of the nanosheets stand nearly perpendicularly on thesubstrate. The {002} lattice planes work just like conducting wires and induce the electronsto transport to the substrate. Chronoamperometry measurement demonstrates an effectiveelectron collection. When the nanostructured photoanode is introduced to dye-sensitizedsolar cells, a conversion efficiency of 3.7% is obtained. The photoanode also has potentialapplication in the other photoelectrochemical systems, such as photocatalytical splitting ofwater.