title: Pseudocapacitive Properties of Two-Dimensional Surface Vanadia Phases Formed Spontaneously on Titania.
abstract: Pseudocapacitive properties of V2O5-based adsorbates supported on TiO2 nanoparticles, which form spontaneously as two-dimensional (2-D) nonautonomous surface phases (complexions) at thermodynamic equilibria, have been systematically measured. Surprisingly, surface amorphous films (SAFs), which form naturally at thermodynamic equilibria at 550-600 °C with self-regulating or "equilibrium" thicknesses on the order of 1 nm, exhibit superior electrochemical performance at moderate and high scan rates (20-500 mV/s) that are of prime importance for supercapacitor applications, as compared with submonolayer and monolayer adsorbates formed at lower equilibration temperatures. This study suggests a new direction to design and fabricate a novel class of supercapacitors and other functional devices via utilizing 2-D interfacial phases that can form spontaneously via facile, cost-effective, and highly scalable synthesis routes.
authors.affiliation: Department of NanoEngineering, Program of Materials Science and Engineering, University of California, San Diego , La Jolla, California 92093-0448, United States.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Samiee
authors.affiliation: Department of NanoEngineering, Program of Materials Science and Engineering, University of California, San Diego , La Jolla, California 92093-0448, United States.
authors.forename: Jian
authors.initials: J
authors.lastname: Luo
keywords: monolayer; pseudocapacitors; submonolayer; surface amorphous film (SAF); symmetric supercapacitor; vanadium oxide