Study of “Doctor Blade” Nano-CuO Photoelectrode for Perspective Water Splitting

A. A. Benedit-Cárdenas; R. Cabrera; A. Fundora; B. González; C. Laza; E. Vigil

A. A. Benedit-Cárdenas Faculty of Physics, University of Havana, 10400 Havana, Cuba http://orcid.org/0000-0003-4569-9305
R. Cabrera Faculty of Physics, University of Havana, 10400 Havana, Cuba http://orcid.org/0000-0003-1059-7640
A. Fundora Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, 10400 La Habana, Cuba http://orcid.org/0000-0001-8809-7529
B. González Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, 10400 La Habana, Cuba http://orcid.org/0000-0002-9051-1204
C. Laza Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, 10400 La Habana, Cuba http://orcid.org/0000-0002-2833-8113
E. Vigil Faculty of Physics & IMRE, University of Havana, 10400 Havana, Cuba http://orcid.org/0000-0003-2623-3673

Abstract

Solar fuels are indispensable for a 100% renewable energy future. Pursuing semiconductor photoelectrodes to obtain H2 using water-splitting photoelectrochemical cells is an important research topic today. Bandgaps as high as 1.9 eV have been reported for nano-CuO because of quantum effects; this favors its possible use for water photolysis. In this paper, nano-CuO films, fabricated using the simple “doctor blade” technique, are studied as photoelectrode in a two-electrode PEC cell for water photolysis. SEM analysis confirm the nanometric size of film grains and the photoelectrode porosity. The photocurrent behavior is studied, particularly, photocurrent transients for non-assisted and assisted water photolysis. Existing defects acting as carrier traps explain the different transient behaviors found. The existence of defects is explored using X-ray diffraction and the Williamson-Hall technique.