Plasma-assisted synthesis of Ag/ZnO nanocomposites: First example of photo-induced H2 production and sensing

Ag/ZnO nanocomposites were developed by a plasma-assisted approach. The adopted strategy exploits the advantages of Plasma Enhanced-Chemical Vapor Deposition (PE-CVD) for the growth of columnar ZnO arrays on Si(100) and Al2O3 substrates, in synergy with the infiltration power of the Radio Frequency (RF)-sputtering technique for the subsequent dispersion of different amounts of Ag nanoparticles (NPs). The resulting composites, both as-prepared and after annealing in air, were thoroughly characterized with particular attention on their morphological organization, structure and composition. For the first time, the above systems have been used as catalysts in the production of hydrogen by photo-reforming of alcoholic solutions, yielding a stable H2 evolution even by the sole use of simulated solar radiation. In addition, Ag/ZnO nanocomposites presented an excellent response in the gas-phase detection of H2, opening attractive perspectives for advanced technological applications.

► Novel approach to supported Ag/ZnO nanocomposites combining RF-sputtering and PE-CVD. ► Low temperature processing with fine control of Ag content/dispersion in ZnO matrix. ► First example of photo-assisted H2 production for Ag/ZnO composites. ► The highest H2 sensing response ever reported for Ag/ZnO systems.