Facile fabrication and photoelectrochemical properties of a one axis-oriented NiO thin film with a (111) dominant facet

Abstract

A facile method was developed for the fabrication of a one axis-oriented p-type NiO monolayer film with a (111) dominant facet on ITO glass. Initially, hexagonal nanoplates of Ni(OH)₂ were synthesized hydrothermally and these nanoplates were assembled as a one axis-oriented monolayered film on ITO glass. Mesoporous NiO with pore diameters of ca. 1.7 nm was obtained by heating the single crystalline Ni(OH)₂ monolayered film at 400 °C for 3 h in air. The (111) facet oriented NiO thin film shows an enhanced photocathodic electrode activity with a photocurrent density of 0.38 mA cm⁻² at a potential of −0.9 V vs. Ag/AgCl. For the first time, a mesoporous NiO thin film with an exposed (111) dominant facet has been fabricated and analyzed for use as a photoelectrode.