Tunable structure of TiO₂ deposited by DC magnetron sputtering to adsorb Cr (VI) and Fe (III) from water

TiO₂ thin films with mixtures of the anatase, rutile, and brookite phases were deposited on glass substrates via magnetron sputtering. Based on XRD and Raman results, the TiO₂-0.47 and TiO₂-3.47 films principally contained the brookite phase, while the TiO₂-1.27 and TiO₂-2.13 films were primarily anatase. The capacities of the TiO₂ films to adsorb heavy metals were tested with Cr(VI) and Fe(III) solutions, and the maximum Cr(VI) and Fe(III) adsorption capacities were realized with the TiO₂-0.47 film (334.5 mg/g) and TiO₂-3.47 film (271.3 mg/g), respectively. SEM‒EDS results revealed the presence of Cr and Fe on the surfaces of the films, thus corroborating the ability of the TiO₂ films to adsorb and remove heavy metals. They are strong candidates for use in wastewater treatment plants.