Abstract
Highly ordered TiO2 nanotube stump-[TiO2 NS]-layers, prepared by anodization of Ti in HF/H3PO4 solutions, were used as a substrate for a thermal dewetting of Au thin films. Depending on the initial Au sputter-deposited layer thickness, various sizes and densities of gold nanoparticles [Au-np] could be obtained on the TiO2 NS. Under certain conditions, very homogeneously distributed Au-np (with diameters in the range of 2-15 nm) can be generated. Such Au-np/TiO2 NS combinations show a high efficiency for H-2 production from H2O/EtOH solutions. A maximum H-2 production efficiency could be obtained from a 2 nm thick Au layer (57.03 mu l H-2 for 9 h) that was dewetted to approximate to 28,000 particles/mu m(2) with individual particle diameters of approximate to 5 nm. (C) 2013 Elsevier B.V. All rights reserved.