Facile synthesis of ZnO nanopencil arrays for photoelectrochemical water splitting

•ZnO nanopencil arrays on FTO substrates was synthesized by an aqueous chemical method.•Oxygen vacancies in these arrays enhance the charge transportation.•A high photocurrent of ~1.3 mA/cm2 at 1 V versus Ag/AgCl was observed.

This paper describes the downward growth of ZnO nanopencil arrays on F-doped SnO2 glass substrates by an aqueous chemical method. The ZnO nanopencil arrays have a unique structure with an abrupt shrinkage in diameter between the tip and the pencil-holder. The ZnO nanopencil arrays yield an elevated photocurrent of ~1.3 mA/cm2 at 1 V versus Ag/AgCl under 100 mW/cm2 illumination (AM 1.5), which is almost 2 times larger than that of the ZnO nanorod arrays. The enhanced photocurrent is attributed to an increased density of oxygen vacancies that could enhance the charge transportation by reducing the electron–hole recombination.

Graphical abstractThis paper describes the downward growth of ZnO nanopencil arrays on F-doped SnO2 glass substrates via an aqueous chemical method for highly efficient photoelectrochemical water splitting.Figure optionsDownload full-size imageDownload as PowerPoint slide