Role of Fe doping in tuning photocatalytic and photoelectrochemical properties of TiO2 for photodegradation of methylene blue

•The undoped and Fe-doped TiO2 nanoparticles were synthesized by sol-gel route.•The Fe-doped TiO2 nanoparticles exhibited high photocatalytic activity.•A method for evaluating the electrochemical performance is proposed.•Room temperature paramagnetic behaviour was observed.•The reduction of band gap from 3.31 eV to 3.10 eV was obtained.