Hydrogen Optical Metamaterial Sensor Based on Pd Dendritic Nanostructures. Issue 13 (30th August 2016)

• Record Type: Journal Article
• Authors: Rocha‐Rodrigues, Pedro; Hierro‐Rodriguez, Aurelio; Guerreiro, Ariel; Jorge, Pedro; Santos, José Luís; Araújo, João Pedro; Teixeira, José Miguel
• Is Part Of: ChemistrySelect. Volume 1:Issue 13(2016)
• Page Start: 3854
• Page End: 3860
• Publication Date: 2016-08-30
• Subjects: hydrogen sensing -- nanowires -- optical metamaterials -- optical sensors -- palladium.; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201600833
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: In this manuscript we present a new type of hydrogen optical metamaterial sensor based on the fabrication of Pd dendritic nanostructures. The fabrication of the sensor relies on a cheap self‐assembly process based on the pulsed electrodeposition method in nanoporous alumina templates. By performing optical transmission measurements, we demonstrate how this sensor can monitor hydrogen gas concentrations at room temperature either by evaluating the rate of signal decay during the Pd hydrogen absorption (transient regime) or by measuring the total variation in signal once the system achieves the equilibrium state (stationary regime). We take into account the effects of the Pd‐hydrogen phase transition and its size dependency to explain the kinetics of the hydrogen absorption and desorption in the studied samples. By using the transient detection method, the sensor is able to detect in approximately 50 s the explosive H2 (g) concentration threshold of 4 % v/v at atmospheric pressure and room temperature. Abstract : A Pd‐based Dendritic optical metamaterial is designed, fabricated and characterized showing potential applications for safe Hydrogen sensing. The system is fabricated by cheap bottom‐up techniques and consists in nanoporous aluminum oxide templates filled with Pd nanowires and dendrites. The anomalous light absorption is responsible for the high sensitivity of the proposed device. Due to the nanometer sizes of dendritic structures, confinement effects are present during Hydrogenation/Dehydrogenation processes which are optically characterized by standard transmission measurements.