Iron (III) and nitrogen co-doped mesoporous TiO2 microspheres (Fe-N-TiO2) are prepared using a self assembly based solvothermal process followed by an ammonothermal method. Among all samples, 1 mol.% of Fe dopants and 500 degrees C nitridation (for 2 h) gives the highest visible light photoactivity. Results imply that the Fe3+/Fe2+ dopant trap energy level introduced within the band gap in mildly Fe (similar to 1 at%) doped TiO2 and the mesoporous nature of the material, both aid in the observed catalytic performance. Subjecting Fe-TiO2 samples to ammonothermal process induces oxygen vancancies, and substitutional and interstitial N. This reduces optical band gap, and introduces local states. The lower band gap and local states together aid in the absorption of visible light and separation of charge carriers. Co-dopants are distributed uniformly in the best photocatalysts. The active species generated in the photocatalytic system is shown to be singlet molecular oxygen (O-1(2)) using selective radical quenchers. (C) 2017 Elsevier B.V. All rights reserved.