Very recently, pseudobrookite Fe₂TiO₅ has been revealed as a promising photocatalyst for the oxidation half-reaction of overall water splitting. This semiconductor is inexpensive, non-toxic, possesses a relatively small band gap, and presents improved structural and photochemical features compared to other well-known photocatalysts. In this investigation, we doped the Fe₂TiO₅ structure with 1.0 at% tin and 1.5 at% niobium, separately, through a solvothermal method to prolong the minority carrier diffusion length and reduce charge recombination events under visible light illumination. The procedure generated single-phase Sn- and Nb-doped Fe₂TiO₅ nanoparticles with dimensions close to 30 nm. In both cases, optical band gap values of 2.1 eV were observed. Pristine Fe₂TiO₅, Sn-doped Fe₂TiO₅, and Nb-doped Fe₂TiO₅ were irradiated by a Xe lamp (λ>400 nm), producing 59.2, 297.6 and 344.0 mmol h^-1 g^-1 of O₂, respectively. This result reflects the substantial improvement that doping Fe₂TiO₅ with Sn and Nb confers to its photocatalytic water splitting activity. In addition, photoelectrochemical measurements in a 1 M NaOH electrolyte indicated photocurrent increments from 2.4 mA cm^-2 at 1.23 V_RHE, for the pristine Fe₂TiO₅, to 36.7 and 70.7 mA cm^-2 at 1.23 V_RHE for Sn- and Nb-doped Fe₂TiO₅, respectively, accompanied by overpotential drops of 0.04 and 0.1V. Electrochemical impedance spectroscopy indicated that reductions in the resistance for the charge carrier transfer resistance at the solid/liquid interface plays an important role for the performance improvement of the doped nanomaterials. Overall, this work illustrates how structural alterations of a potential photocatalyst can improve photochemical energy conversion. The authors acknowledge support from FAPESP (Grant 2017/11986-5) and Shell and the strategic importance of the support given by ANP (Brazil’s National Oil, Natural Gas and Biofuels Agency) through the R&D levy regulation.