Enhanced photocatalytic activity of TiO2 nano-structured thin film with a silver hierarchical configuration

Layered Fe(III) doped TiO2 thin-film electrodes for the photoelectrocatalytic oxidation of glucose and potassium hydrogen phthalate

“…EIS Nyquist plots are commonly used to investigate charge transport resistance and exciton separation efficiency [23]. The size of the arc radius on the EIS Nyquist plot indicates the rate of photoelectrochemical reaction at the electrode [24], and is a useful parameter for characterizing electron transport resistance [16]. Figure 2 shows impedance spectra of different TiO 2 film electrodes under UV illumination with light intensity of 6.2 mW cm -2 in aqueous 0.1 mol L -1 NaNO 3 .…”

“…The photoelectrochemical behavior of the TiO 2 electrodes was further characterized with LSV measurements in aqueous 0.1 mol/L NaNO 3 under the constant UV illumination [14]. The photocurrent originates from the photooxidation of water and organic compounds within the electrolyte, and photocurrent density corresponds to the amount of free carriers under the same potential bias, which is related to the amount of photo-generated holes within the TiO 2 electrode [16]. LSV curves of the TiO 2 electrodes are shown in Figure 3.…”

“…The TiO 2 sol was prepared by the hydrolysis of tetrabutyl titanate as described in our previous report 16. Briefly, 68 mL of tetrabutyl titanate and 16.5 mL of diethanolamine were dissolved in 210 mL of absolute ethanol, with the mixture stirred vigorously for 1 h at room temperature (solution A).…”

“…anatase/rutile) may possess higher activity in *Corresponding author (email: s.zhang@griffith.edu.au) the photoelectrocatalytic degradation of organic compounds than pure anatase electrodes because the electron-transfer pathway from anatase phase to rutile phase facilitates the separation of photoelectron and photohole, extending the lifetime of the photoelectron and photohole [14]. Other TiO 2 modifications such as Pt 15 and Ag 16 doping have also been shown to improve organic degradation efficiency in photoelectrocatalytic processes, perhaps due to the Pt or Ag nanoparticles acting as electron traps and preventing exciton recombination.…”

“…Our studies [16][17][18][19][20][21] indicated that both metal ion type and the doped composite hierarchical structure affected photoelectrocatalytic activity. The layered structure that favored the formation of the electron flow gradient was beneficial for the improvement of exciton separation and, therefore, photoelectrocatalytic activity [16][17][18][19][20][21].…”