Controlled synthesis of anatase TiO2 octahedra with enhanced photocatalytic activity

Abstract Titanium dioxide (TiO 2 ) nanocrystals with specific exposed crystal facet have attracted considerable interest due to their promising applications in the fields of energy and environment. In this paper, we report on a simple solvothermal approach for the synthesis of anatase TiO 2 octahedra with high yield, using titanium(IV) sulfate and hydrazine hydrate as the starting materials. The formation mechanism of anatase TiO 2 octahedra is suggested. The samples were characterized with XRD, Raman, SEM, TEM, FTIR, XPS, and UV/vis techniques, and further tested as a candidate in photocatalysis to decompose methyl orange in aqueous solution at room temperature. The results show that SO 4 2− ions not only benefit the formation of octahedral nanocrystals, but also inhibit nitrogen doping into TiO 2 matrix. More importantly, it is found that the octahedral TiO 2 nanocrystals show enhanced photocatalytic activity compared to TiO 2 P25 and anatase TiO 2 counterparts.