부산대학교 도서관

New metal oxide-metal chalcogenide system composed of TiO2@SnSe-ZnS composite was synthesized via one-step solvothermal process. XRD, FTIR, and Raman results confirmed the presence of mixed phases and corresponding molecular bonding of rutile TiO2, cubic ZnS, and orthorhombic SnSe. FESEM and TEM characterizations showed a unique interference between two distinguished morphologies, where TiO2 appeared as nanoflakes covering the spherical particles of ZnS/SnSe. XPS inspection of TiO2-modified SnSe-ZnS sample showed that small portion of the existed Zn2+ in tetrahedral sites is displaced into the octahedral sites as a result of the lattice distortion by incorporation of Ti4+/Ti3+ cations and oxygen deficiency in the structure. The initial specific discharge capacity for the modified SnSe-ZnS anode with 3% TiO2 was significantly increased from 770 to 805 mAh.g−1. The progressive cycling of the non-modified SnSe-ZnS anode possessed significant capacity fading, while the modified SnSe-ZnS anode with 3% TiO2 showed high capacity retention up to 100 mAh.g−1 after hundred cycles at 0.1 A.g−1.