Work

Remarkable adsorption-photocatalytic performance for methylene blue degradation by self Fe-doped TiO2 nanotubes derived from Bornean ilmenite

Year: 2025

Type: article

Abstract: The synthesis of titanium dioxide (TiO₂) nanotubes from natural ilmenite minerals has garnered significant research interest due to its abundance and low cost. This study explores a controlled process to transform ilmenite into TiO₂ nanotubes, leveraging its inherent properties. Ilmenite was processed via hydrometallurgy technique using the sulfate route after mechanical activation. The resulting leachate solution containing TiOSO₄ was further hydrolized to form TiO₂ nanoparticles which were subsequently converted into nanotubes through hydrothermal treatment at 150°C in 10 M NaOH for 24 h. The as-synthesized product, displayed tubular morphology, with inner and outer diameters of 3.75 ± 0.61 nm and 9.35 ± 1.50 nm, respectively, and a length ranging from 30 to 120 nm, and a high specific surface area of 256.81 m²/g, classifying it as mesoporous. The optical study revealed a band gap energy of 2.80 eV, influenced by natural iron doping (0.94 wt%), while photoluminescence analysis indicated a reduced electron-hole recombination rate. Photocatalytic performance, assessed through methylene blue (MB) degradation, achieved up to 98 % removal under combined dark and visible light conditions within 120 min. The improved adsorption is attributed to the material’s tubular structure and high surface area, while photocatalytic enhancement is primarily influenced by the narrowed bandgap and suppressed electron–hole recombination. These findings underscore the synergistic contribution of adsorption and photocatalysis in organic pollutant degradation and highlight the potential of ilmenite-derived TiO₂ nanotubes in environmental remediation applications. In this study, TiO₂ nanotubes were synthesized from a natural source—ilmenite mineral—through a three-step process: (1) extraction, (2) synthesis of TiO₂ nanoparticles, and (3) synthesis of TiO₂ nanotubes. The resulting TiO₂ nanotubes demonstrated superior characteristics compared to those synthesized from the commercial precursor Degussa P25. These advantages include a higher specific surface area, a lower band gap energy, and a reduced electron-hole recombination rate. These enhanced properties contribute to the improved photocatalytic performance in degrading the synthetic dye methylene blue, where TiO₂ nanotubes derived from ilmenite achieved a degradation efficiency of up to 98 %, in contrast to only 88 % for those synthesized from commercial materials under 120 min of irradiation. • TiO₂ nanotubes were synthesized from local Indonesian ilmenite. • They show a specific surface area of 256.81 m²/g and a band gap of 2.80 eV. • Methylene blue degradation reached 98 % under visible light irradiation.

Source: Next Materials

DOI: 10.1016/j.nxmate.2025.101447