author = "Zanetti, Sonia Maria and Rocha, Kleper de Oliveira and Rodrigues, 
                         Jos{\'e} Augusto Jorge and Longo, Elson",
          affiliation = "{SENCER - Sensores Cer{\^a}micos Ltda} and {SENCER - Sensores 
                         Cer{\^a}micos Ltda} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)} and {Universidade Estadual Paulista (UNESP)}",
                title = "Soft-chemical synthesis, characterization and humidity sensing 
                         behavior of WO3/TiO2 nanopowders",
              journal = "Sensors and Actuators B: Chemical",
                 year = "2014",
               volume = "190",
                pages = "40--47",
             keywords = "EXAFS, Extended Xray absorption fine structure (EXAFS) 
                         spectroscopies, Polymeric precursor methods, Situ XANES, 
                         Structural and surface characterization, Temperature-programmed 
                         reduction, WO<sub>3</sub>/TiO <sub>2</sub>, X-ray absorption near 
                         edge spectroscopy, Chemisorption, Electric properties, Extended X 
                         ray absorption fine structure spectroscopy, Humidity sensors, 
                         Nanostructured materials, Polymers, Pore size, Spectrometry, 
                         Synthesis (chemical), Transmission electron microscopy, X ray 
                         diffraction, X ray powder diffraction, Titanium dioxide.",
             abstract = "Tungsten oxide/titania (WO3/TiO2) nanopowders were synthesized by 
                         the polymeric precursor method which varied the WO3 content 
                         between 0 and 10 mol%. The powders were thermally treated in a 
                         conventional furnace and their structural, microstructural and 
                         electric properties were evaluated by X-ray diffraction (XRD), 
                         Raman spectrometry, N 2 physisorption, NH3 chemisorption, 
                         temperature-programmed reduction (TPR), X-ray absorption near-edge 
                         spectroscopy (XANES) in situ XANES and extended X-ray absorption 
                         fine structure spectroscopy (EXAFS) and transmission electron 
                         microscopy (TEM). XRD and Raman spectrometry confirmed the 
                         homogeneous distribution of an amorphous WO3 phase in the TiO 2 
                         matrix which stabilized the anatase phase through the generation 
                         of [TiO5V0] or [TiO5V 0] complex sites. Conventional TPR-H2 
                         (temperature programmed reduction) along with XANES TPR-H2 and 
                         XANES TPR-EtOH showed that WO3/TiO2 sample reduction occurs 
                         through the formation of these complex clusters. Moreover, the 
                         addition of WO3 promoted an increase in the surface acidity of 
                         doped samples as revealed by NH3 chemisorption. The WO3/TiO2 
                         bulk-ceramic samples were further used to estimate their potential 
                         application in a humidity sensor in the range of 15-85% relative 
                         humidity. Probable reasons that lead to the different humidity 
                         sensor responses of samples were given based on the structural and 
                         surface characterizations. Correlation between the sensing 
                         performance of the sensor and its structural features are also 
                         discussed. Although all samples responded as a humidity sensor, 
                         the W2T sample (2 mol% added WO3) excelled for sensitivity due to 
                         the increase in acid sites, optimum mean pore size and pore size 
                  doi = "10.1016/j.snb.2013.08.053",
                  url = "http://dx.doi.org/10.1016/j.snb.2013.08.053",
                 issn = "0250-6874",
                label = "scopus 2014-05 ZanettiRochRodrLong:2014:SoSyCh",
             language = "en",
           targetfile = "1-s2.0-S0925400513009891-main.pdf",
                  url = "http://dx.doi.org/10.1016/j.snb.2013.08.053",
        urlaccessdate = "26 nov. 2020"