We report a simple scheme to fabricate organic/inorganic hybrid nanostructures with extraordinary morphologies by one-step spin coating, using a PS-b-PEO diblock copolymer as template coupled with sol-gel chemistry. The shape and size of the titania nanoobject can be fine-tuned by controlling the amount of sol-gel precursor relative to PS-b-PEO and the composition of the precursor. Ordered arrays of nanoscopic titania objects such as nanodots, nanobowls, and nanonetworks were obtained from the initial hybrid nanostructures by removing the organic matrix by UV treatment. Photocatalytic activities of the resulting titania nanoobjects were investigated in terms of the degradation of a typical dye. {graphics}