Core-shell gold nanoparticles and gold-decorated metal oxides for gas sensing applications

Core-shell Gold nanoparticles exhibit tremendous catalytic properties and chemical reactivity, and have been extensively employed in a number of applications. Hereby we report different approaches to synthesize core-shell Gold nanoparticles; namely, wet-chemical reduction of Au-salts and Sacrificial Anode Electrolysis, with the intended use of Gold nanoparticles as catalysts and active layers on field effect capacitive devices for nitrogen oxides detection. In addition, different metal oxides are electrochemically decorated with nano-Gold to prepare metal-metal oxide nanocomposites. These nano-structured materials are fully characterized using TEM, SEM, and XPS, which reveal the formation of nanoscale Gold, and its successful decoration on metal oxide nanoparticles. The XPS results obtained after thermal annealing demonstrate that Gold nanoparticles are extremely stable even after 2h of annealing at high temperature (≤ 550°C).