Superior adsorption and photodegradation of eriochrome black-T dye by Fe3+ and Pt4+ impregnated TiO2 nanostructures of different shapes

•Nanotubes displayed lower adsorption efficiency than P25–TiO2 and nanorods.•Ionic interactions between oppositely charged particles enhance adsorption rate.•Extra positive charge by Fe3+ and Pt4+ impregnation improved adsorption capacity.•Adsorption by various TiO2 nanostructures fits Langmuir and frendluich isotherms.•Pt4+ loaded P25–TiO2 exhibited highest EBT photodegradation efficiency.

This article highlights comparative adsorption behavior and photocatalytic activity of TiO2 nanostructures (P25, nanorods and nanotubes) for degradation of eriochrome black-T dye (EBT) depending on their structural morphology and metal ions (Fe3+ and Pt4+) deposition. Enhancement in adsorption capacity (qmax) was observed due to impartment of extra positive charges by Fe3+ and Pt4+ impregnation and follow the order, Pt4+–P25–TiO2 (400 μg/mg) > Fe3+–P25–TiO2 (344 μg/mg) > P25–TiO2 (248 μg/mg) > nanotubes (123 μg/mg) > nanorods (69 μg/mg). The Fe3+ and Pt4+ loaded TiO2 improved dye adsorption and degradation rate of EBT undergoing complete minerization to CO2 under UV light irradiation.

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