Ultrathin TiO2(B) Nanosheets as the Inductive Agent for Transfrering H2O2 into Superoxide Radicals

A reflux method to synthesize ultrathin polycrystalline TiO2(B) nanosheets (NSs) which are assembled by single crystals, and further stacked into nanoflower structures, is described. On the basis of the theoretical calculations and experiments, H2O2 can easily substitute the ethylene glycol adsorbed on the surface of TiO2(B) NSs, forming H2O2 NS due to the lower adsorption energy and the unique structural features of ultrathin TiO2(B) nanosheets. TiO2(B) NSs and the H2O2 system can be accelerated to generate superoxide radicals under heat or light and thus exhibit a great degradation property on dye molecules; the total organic carbon (TOC) removal rate was 6 times higher than that for H2O2 alone. Meanwhile, TiO2(B) NSs and the H2O2 system have a good application on the selective oxidation due to the reactive species of superoxide radicals avoiding over oxidization of benzyl alcohol. The conversion of benzyl alcohol oxidized to benzaldehyde in water solution under low temperature and atmospheric pressure was 51.13%, while the selectivity was dose to 100%. We believe that the present findings will provide valuable methods for highly efficient generation of superoxide radicals and broaden their applications in catalysis.