On the photocatalytic degradation of phenol and dichloroacetate by BiVO4: The need of a sacrificial electron acceptor

The photodegradation of phenol and dichloroacetic acid (DCAA) by \ce{BiVO4} was studied in the absence as well as presence of selected electron scavengers. The experiments were performed under the visible (vis) irradiation of aqueous solutions over a wide pH range (1--13). Phenol was photocatalytically degraded by \ce{BiVO4} into \emph{p}-benzoquinone below pH~3 and into an open-ring structure at pH~13. Methylene blue (MB) accelerated the reaction below the isoelectric point of \ce{BiVO4} and did not undergo significant degradation. In presence of \ce{H2O2}, phenol was rapidly degraded up to pH~9. The degradation rates are two orders of magnitude higher than in absence of electron scavenger. The degradation of dichloroacetic acid was only possible in presence of \ce{H2O2}. High initial concentrations of \ce{H2O2} inhibit the reaction and its consumption is very fast. Sequential additions of this sacrificial electron acceptor (SEA) enables the total degradation of a 1~mM DCAA solution.


Published in:
Journal of Photochemistry and Photobiology A: Chemistry, 216, 2-3, 221-227
Year:
2010
Publisher:
Elsevier
ISSN:
1010-6030
Keywords:
Laboratories:




 Record created 2010-12-16, last modified 2018-09-25


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