Ternary transition titanium-niobium trisulfide as photoanode for assisted water splitting
| Autor: | Eduardo Flores, I. J. Ferrer, J.R. Ares, Carlos Sánchez |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Band gap Niobium Analytical chemistry chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Catalysis 0104 chemical sciences Dielectric spectroscopy chemistry Water splitting 0210 nano-technology Ternary operation Electronic band structure Absorption (electromagnetic radiation) Monoclinic crystal system |
| Zdroj: | Catalysis Today. :107-112 |
| ISSN: | 0920-5861 |
| DOI: | 10.1016/j.cattod.2018.01.024 |
| Popis: | Ternary titanium-niobium trisulfide, [TixNb1-xS3 (Nb rich) and NbxTi1-xS3 (Ti rich), x 1 ¯ 2), respectively, the structure of the ternary trisulfide depends on the dominant presence of one of the metals: Ti (monoclinic (P21/m)) or Nb (triclinic (P 1 ¯ )). Optical absorption coefficients were determined from reflectance and transmittance measurements. The TixNb1-xS3 and NbxTi1-xS3 direct optical bandgap energies obtained are 1.0±0.1 eV. Photoelectrochemical measurements in 0.5 M Na2SO3 with a platinum counter electrode have been carried out to characterize the semiconductor/electrolyte interface. The flat band potentials (TiS3-Vfb = -0.64 ± 0.02V NHE, NbS3-Vfb = -0.73 ± 0.02V NHE, NbxTi1-xS3-Vfb = -0.63 ± 0.05V NHE and TixNb1-xS3V-fb = -0.72 ± 0.05V NHE) have been measured by Electrochemical Impedance Spectroscopy (EIS) and they have been used, beside the bandgap energy, to depict the energy band levels scheme. Hydrogen fluxes (photogenerated under 200 mW/cm2 white light illumination in a PEC at 0.3 V bias potential) have been quantified as a function of illumination time by quadrupole mass spectrometry (QMS) reaching values up to 2.2±0.1 μmolH2/min⋅cm2 in the best scenario. |
| Databáze: | OpenAIRE |
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