Electronic structure exploration of active element surface for hydrogen sensor based on wo3-x nanoparticles

Abstract

Nanopowders of nonstoichiometric tungsten oxides were synthesized by method of electric explosion of conductors (EEC). Their electronic and atomic structures were explored by XPS and TEM methods. It was determined that mean size of nanoparticles is d=10-35 nm, their composition corresponds to protonated nonstoichiometric hydrous tungsten oxide WO2.91(OH) 0.09, there is crystalline hydrate phase on the nanoparticles' surface. After anneal a content of OH-groups on the surface of nonstoichiometric samples is higher than on the stoichiometric ones. High sensitivity of the hydrogen sensor based on WO2.91·(OH)0.09, at 293 K can be connected with forming of proton conductivity mechanism. © 2007 Springer.