Electrochemical synthesis of cuprous oxide on highly conducting metal micro-pillar arrays for water splitting

Abstract

Three-dimensional (3D) metal/cuprous oxide (Cu2O) micro-pillar arrays were fabricated by electroless deposition of Ni on Si micro-pillars followed by the electrochemical deposition of Cu2O on the metal micro-pillars. The metal micro-pillars with heights of 16 mm and diameters of 1-1.5 mm showed low reflectance and conductance values similar to Cu2O plates, indicating that the 3D metal/Cu2O micro-pillars are good current collectors. The photocurrent of the 3D metal/Cu2O micro-pillar arrays was more than twice that of the Cu2O plates. This high photocurrent for the 3D metal/Cu2O micro-pillar results from its large surface area, long optical absorption depth (micro-pillar length) and short carrier diffusion length (thin Cu2O absorber). (C) 2016 Elsevier B.V. All rights reserved.