Photoelectrochemical water splitting properties of a vertically aligned ZnO nanosheet

Abstract

The vertically aligned ZnO nanosheet is used as the photoanode in photoelectrochemical water splitting in this study. A nanosheet is a 2D structure which offer improvement over a 1D counterpart such as nanorod or nanowire in terms of increasing the active surface area while still maintain the beneficial electron transport properties to some degree. Furthermore, by growing the nanosheet in vertically aligned manner, the surface area can be larger than the horizontally grown counterpart. In this study, the electrodeposition method is used to grow the vertically aligned ZnO nanosheet. Galvanostatic mode is used with current density of -1, -3 and -5 mA/cm2 applied for 1500, 500 and 300 s, respectively (same amount of charge density). The obtained structure is the nanosheet layer as a majority part grows on top of an under- layer. The height of the nanosheet and the morphology of the under-layer are affected by the current density applied during the electrodeposition. The effect of the unique structure as the photoanode in photoelectrochemical water splitting is discussed.