English: Earlier research found that 3D morphologies developed using a low-cost microwave synthesis technique were not retained during the transformation of titanium dioxide (TiO2) by annealing titanium glycerolate (TGy) powder resulting in low photoelectron conversion efficiencies in dye-sensitized solar cell (DSSCs) devices. This study overcame the challenge, and FESEM imaging showed that 3D morphologies were retained after annealing via the same microwave method and the solvent system by using urea as an aid for a structure-preserving/structure-tuning agent. The morphological tuning and N-doping resulted in the 3D hierarchical titanium dioxide nanostructures, including Gomphrena globosa flower-like and blossomed flower of Dahlia pinnata-like morphologies, and other 3D features. The diffusion of N in the TiO2 matrix was confirmed from XPS and EDX and was also reflected in optical absorption characteristics. The binder-free TiO2 pastes have been prepared from the synthesized TiO2 nanopowders that were employed in the screen printing. The screen-printed photoanodes were used to assemble DSSC devices. The output performances of DSSC reveal the influence of the nitrogen doping in relation to the undoped TiO2-based device. The G globosa flower-like TiO2 nanostructured photoanode exhibited the most pronounced enhancement in short-circuit current density and an increase in the maximum power conversion efficiency, by nearly a factor of 2 compared to pure TiO2. Jayapal, V, Rangasamy, S, Venkidusamy, S, Venkatesan, R, Mayandi, J, Pearce, JM. The use of urea as an N-doping 3D hierarchical preserving agent for titanium dioxide nanostructures tailored for dye-sensitized solar cells. International Journal of Energy Research 2022; 46(7): 9533-9548. https://doi.org/10.1002/er.7823 OA academia