Photoelectrochemical performance of birnessite films and photoelectrocatalytic activity toward oxidation of phenol
Huiqin Zhang
,
Hongrui Ding
,
Xin Wang
,
Cuiping Zeng
,
Anhuai Lu
,
Yan Li
,
Changqiu Wang
DOI:10.1016/j.jes.2016.04.009
Received February 05, 2016,Revised April 01, 2016, Accepted April 11, 2016, Available online May 05, 2016
Volume 29,2017,Pages 259-267
Birnessite films on fluorine-doped tin oxide (FTO) coated glass were prepared by cathodic reduction of aqueous KMnO4. The deposited birnessite films were characterized with X-ray diffraction, Raman spectroscopy, scanning electron microscopy and atomic force microscopy. The photoelectrochemical activity of birnessite films was investigated and a remarkable photocurrent in response to visible light was observed in the presence of phenol, resulting from localized manganese d–d transitions. Based on this result, the photoelectrocatalytic oxidation of phenol was investigated. Compared with phenol degradation by the electrochemical oxidation process or photocatalysis separately, a synergetic photoelectrocatalytic degradation effect was observed in the presence of the birnessite film coated FTO electrode. Photoelectrocatalytic degradation ratios were influenced by film thickness and initial phenol concentrations. Phenol degradation with the thinnest birnessite film and initial phenol concentration of 10 mg/L showed the highest efficiency of 91.4% after 8 hr. Meanwhile, the kinetics of phenol removal was fit well by the pseudofirst-order kinetic model.
