Optical hydrogen sensing with modified Pd-layers: A kinetic study of roughened layers and dewetted nanoparticle films

Thin palladium layers with thickness of 5, 8, 14 or 18 nm were sputtered on fused silica slides. Heat treatment procedures were performed to increase the optical response of palladium layers during purging with hydrogen. First, the layers were oxidized and additionally reduced with hydrogen, to modify the layer roughness. Second, a 5 nm thick layer was dewetted to obtain nanoparticles. This leads to an increase of the optical response by up to the factor of 16. Additionally, the type of the optical response has changed in the case of the nanoparticle layers. The light transmission was determined with simple and inexpensive measuring instrument, described in detail in this article. (C) 2014 Elsevier B.V. All rights reserved.