Several mesoporous TiO₂ (MT) materials were synthesized under different conditions following a hydrothermal procedure using poly(ethylene-glycol)-block-poly(propylene-glycol)-block-poly(ethylene-glycol) (P123) as the template and titanium isopropoxide as the titanium source. The molar ratios of Ti/P123, and the pH values of the reaction solution in an autoclave were investigated. Various techniques such as Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), laser Raman spectrometry (LRS), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) were used to characterize the products. Then, these materials were assembled into dye-sensitized solar cells (DSSCs). Analysis of the J–V curves and electrochemical impedance spectroscopy (EIS) were applied to characterize the cells. The results indicated that the specific surface area and crystalline structure of these materials provide the possibility of high photocurrent for the cells, and that the structural characteristics of the specimens led to increased electron transfer resistance of the cells, which was beneficial for the improvement of the photovoltage of the DSSCs. The highest photoelectric conversion efficiency of the cells involving MT materials reached 8.33%, which, compared with that of P25-based solar cell (5.88%), increased by 41.7%.