Photoelectrocatalytic removal of bromate using Ti/TiO2 coated as a photocathode.
These studies represent the rare use of a TiO2 material as a photocathode and the first application of photoelectrocatalysis for BrO3- removal. Photoelectrocatalytic reduction of BrO3- to Br- can reach 70% at neutral pH under an applied potential of -0.20 V versus SCE (saturated calomel electrode) after 75 min on the irradiated nanoporous thin-film TiO2-coated working electrode, which presented a flat band potential of -0.0274 V versus SCE. Regardless of the potential applied in these experiments, no BrO3- removal was observed in the counter electrode compartment or during electrolysis or photocatalysis, confirming that reduction of BrO3- to Br requires the combination of a negative potential (ideally near -0.20 V) and ultraviolet irradiation of the Ti/TiO2 electrode. The process was selective for BrO3- removal in that this process did not significantly reduce levels of Ca2+ and Mg2+ in drinking waters.
Departamento de Química Analítica - Instituto de Química - Universidade Estadual Paulista, Av. Prof. Francisco Degni, s/n, C. P. 358, 14801-970 Araraquara, SP, Brazil.
Fabiana Maria Monteiro
FM
Paschoal
Greg
G
Pepping
Maria Valnice Boldrin
MV
Zanoni
Marc A
MA
Anderson
D001959:Bromates / Q000737:chemistry*; D002384:Catalysis; D055664:Electrochemical Techniques; D004566:Electrodes; D010777:Photochemistry; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
D001959:Bromates; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium