Photoelectrocatalytic Activity of ZnO-Modified Hematite Films in the Reaction of Alcohol Degradation

Thin-film nanocrystalline hematite electrodes were fabricated by electrochemical deposition and loaded with electrodeposited zinc oxide in various amounts. Under visible light illumination, these electrodes demonstrate high activity in the photoelectrochemical degradation of methanol, ethylene glycol and, in particular, glycerol. Results of intensity-modulated photocurrent spectroscopy show that the photoelectrocatalysis efficiency is explained by the suppression of the electron-hole pair recombination and an increase in the rate of photo-induced charge transfer. Thus, zinc oxide can be considered an effective modifying additive for hematite photoanodes.

Photoelectrocatalytic Properties of a Ti-Modified Nanocrystalline Hematite Film Photoanode

Photoelectrocatalytic oxidation of methanol, ethylene glycol, glycerol, and 5,6,7,8-tetrahydro-2-naphthol on thin-film nanocrystalline hematite electrodes fabricated by electrochemical deposition and promoted with spin-coated titanium has been studied. It is shown that the modification of hematite transforms it into material exhibiting high activity in the photoelectrochemical process of substrate oxidation upon illumination with light in the visible region of the spectrum. The highest activity is observed in the reaction of photoelectrocatalytic oxidation of glycerol. Results of intensity-modulated photocurrent spectroscopy (IMPS) suggest that the effect is due to an increased rate of charge transfer in the process of photoelectro-oxidation and efficient suppression of the recombination of generated electron-hole pairs. Therefore, thin-film photoanodes based on modified hematite are promising for practical application in the photooxidation of glycerol, a by-product of biofuel production, as well as in the photoelectrochemical degradation of other organic pollutants, including those formed during the production of pharmaceuticals.