Enhancing Tungsten Oxide Gasochromism with Noble Metal Nanoparticles: The Importance of the Interface. Issue 6 (4th December 2022)

• Record Type: Journal Article
• Authors: Longato, Alessandro; Vanzan, Mirko; Colusso, Elena; Corni, Stefano; Martucci, Alessandro
• Is Part Of: Small. Volume 19:Issue 6(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-04
• Subjects: hydrogen sensing -- interfaces -- metal nanoparticles -- optical sensors -- spillover -- tungsten oxide; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202205522
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Crystalline tungsten trioxide (WO3 ) thin films covered by noble metal (gold and platinum) nanoparticles are synthesized via wet chemistry and used as optical sensors for gaseous hydrogen. Sensing performances are strongly influenced by the catalyst used, with platinum (Pt) resulting as best. Surprisingly, it is found that gold (Au) can provide remarkable sensing activity that tuned out to be strongly dependent on the nanoparticle size: devices sensitized with smaller nanoparticles display better H2 sensing performance. Computational insight based on density functional theory calculations suggested that this can be related to processes occurring specifically at the Au nanoparticle‐WO3 interface (whose extent is in fact dependent on the nanoparticle size), where the hydrogen dissociative adsorption turns out to be possible. While both experiments and calculations single out Pt as better than Au for sensing, the present work reveals how an exquisitely nanoscopic effect can yield unexpected sensing performance for Au on WO3, and how these performances can be tuned by controlling the nanoscale features of the system. Abstract : When functionalized with gold and/or platinum nanoparticles, tungsten trioxide thin films can serve as optical sensors for hydrogen detection. By means of experimental and computational investigations, we were able to assess the role the metal species and nanoparticle dimension have toward the device performances, proposing a novel mechanism for hydrogen sensing which highlight the fundamental importance of the metal‐oxide interface.