Titanium dioxide （TiO2）, which is the widely used photo-catalyst, has been synthesized by simple hydrothermal solution containing tetrabntyl titanate and hydrofluoric acid. The synthesized product has been applied to photo-degradation in aqueous phase of chlorinated solvents, namely tetra- chloroethene （PCE）, tdchloroethene （TCE） and 1,1,l-trichloroethane （TCA）. The photo-degradation results revealed that the degradation of these harmful chemicals was better in UV/synthesized TiO2 system compared to UV/commerciai P25 system and UV only system. The photo-catalytic efficiency of the synthesized TiO2 was 1.4, 1.8 and 3.0 folds higher compared to the commercial P25 for TCA, TCE and PCE degradation, respectively. Moreover, using nitrobenzene （NB） as a probe of hydroxyl radical （.OH）, the degradation rate was better over UV/synthesized TiO2, suggesting the high concentration of .OH generated in UV/synthesized TiO2 system. In addition, .OH concentration was confirmed by the strong peak displayed in EPR analysis over U~/synthesized TiO2 system. The characterization result using XRD and TEM showed that the synthesized TiO2 was in anatase form and consisted of well-defined sheet-shaped structures having a rectangular outline with a thickness of 4 rim, side length of 50 nm and width of 33 nra and a surface 90.3 m^2/g. XPS analysis revealed that ≡Ti-F bond was formed on the surface of the synthesized TiO2. The above results on both photocatalytic activity and the surface analysis demonstrated the good applicability of the synthesized TiO2 nano-sheets for the remediation of chlorinated solvent contaminated groundwater.
Landry Biyoghe Bi NdongMurielle Primaelle IbondouZhouwei MiaoXiaogang GuShuguang LuZhaofu QiuQian SuiSerge Maurice Mbadinga
