Excellent nitroarene reduction activity of ilmenite nanochips prepared by facile template-free hydrothermal synthesis

Aiming at demonstrating the highly-efficient catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP), we synthesized the ilmenite (FeTiO₃) nanochips by using the facile template-free hydrothermal growth technique, and characterized their material properties and catalytic reduction activities. To investigate the effects of the hydrothermal reaction temperatures on the morphological, textural, and 4-NP reduction characteristics, the rhombohedral FeTiO₃ nanochips were prepared at three different temperatures of 120, 150, and 180 °C. Among them, the FeTiO₃ nanochips prepared at 180 °C displayed to possess more homogeneous distributions in their morphological shape and average size, compared to those of other samples. Furthermore, the high porosity (i.e., specific surface area: 95.3 m²/g, total pore volume: 0.1275 cm³/g) and the high charge transfer activity (Fe²⁺ + Ti⁴⁺ → Fe³⁺ + Ti³⁺) of the 180 °C-synthesized FeTiO₃ nanochips enabled us to demonstrate the excellent 4-NP–to–4-AP reduction performances with a high reduction rate (∼91%) for a short reduction time (6 min). The results advocate that the FeTiO₃ nanochips can be effectively utilized as a 4-NP reduction catalyst for future environmental technology.