Differences in hydrogen absorption over Pd and Pt functionalized CVD-grown GaN nanowires

In this study, we report the differences in hydrogen (H-2) absorption properties of platinum (Pt) and palladium (Pd) functionalized gallium nitride (GaN) nanowires via gas sensing studies. GaN nanowires of similar to 25 - 200 nm diameter and similar to 50 - 75 gm length are grown uniformly over large area (10 x 10 mm(2)) using Au assisted chemical vapour deposition technique. The nanowires are grown at 900 for 2 h using gallium (Ga) as source material and ammonia (NH3) as the reacting gas. The nanowires are functionalized with Pd and Pt nanoclusters using solution technique. H-2 absorption by these functionalized nanowires which is manifested as gas sensing response is compared in the temperature range of 50-200. The role of surface kinetics in Pd and Pt is shown to be responsible for the difference in the sensor response. (C) 2018 Elsevier B.V. All rights reserved.