Elektrochemická, fotoelektrochemická a spektroelektrochemická charakterizace nanomateriálů

• Main Author: Pitňa Lásková, Barbora
• Other Authors: Kavan, Ladislav
• Format: Doctoral Thesis
• Language: English
• Published: 2017
• Online Access: http://www.nusl.cz/ntk/nusl-369541

Titanium dioxide (TiO2) and spinel Li4Ti5O12 belong to widely studied semiconducting metal oxides. Nanocrystalline TiO2 and Li4Ti5O12 are attractive materials for applications in Li-ion batteries and the former also for photoelectrochemical solar cells. Moreover, spinel Li4Ti5O12 could be a promising material for Na-ion batteries too, because of possible accommodation of larger Na+ ions (compared to Li+ ). The nanocrystalline TiO2 anatase with a predominant {001} facet was studied electrochemically by cyclic voltammetry of Li+ insertion and by chronoamperometry and compared with anatase materials with dominating {101} facet. Both voltammetric and chronoamperometric diffusion coefficients and activation energies proved higher activity of anatase {001} nanosheets toward Li+ insertion than that of the usual anatase nanoparticles exposing the {101} facet. Subsequently, the flatband potential and electron kinetics of TiO2 anatase nanocrystals with mostly exposed facet {101} or {001} were compared. The anatase {001} nanoplatelets exhibited more negative flatband potential, higher chemical capacitance and longer electron lifetime than anatase {101} nanoparticles. The Li+ insertion into TiO2 anatase nanoparticles was studied by Raman spectroscopy and by in situ Raman spectroelectrochemistry. Four...