Preparation of morphology-controlled TiO 2 nanocrystals for the excellent photocatalytic activity under simulated solar irradiation

Abstract A simple synthetic approach based on solvothermal technique and hydrogenation was developed for preparation of TiO 2 nanocrystals with different morphologies such as elongated rhombic, dog-bone, oval and core-shell structured oval. The effect of oleic acid (OA) and oleylamine (OM) as two capping surfactants on the growth of TiO 2 nanocrystals was investigated. The physicochemical properties of the obtained samples were characterized by various techniques including TEM, XRD, UV–vis absorption, Raman, XPS, BET, PL and photocurrent measurement. In photodegradation of RhB under simulated solar irradiation, the oval-shaped TiO 2 nanocrystals with core-shell structure (co-TiO 2 ) was superior to other TiO 2 nanocrystals in catalytic activity. Moreover, the co-TiO 2 nanocrystals exhibited well recyclability during multiple photocatalytic tests. These excellent properties of co-TiO 2 were attributed to its special structure, including lattice-disordered surface layer and well-crystallized lattice core, and narrow band gap (2.67 eV).