Facile synthesis of ZnO nanopencil arrays for photoelectrochemical water splitting

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 similar to 1.3 nnA/cm(2) at 1 V versus Ag/AgCl under 100 mW/cm(2) 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. (C) 2014 Elsevier Ltd. All rights reserved.