Synthesis of TiO2 nanotubes from ilmenite with CuS nanoparticles as efficient visible-light photocatalyst

• Published in: Environmental science and pollution research international 2023-09, Vol.30 (42), p.96400-96411
• Main Authors: Abbaspour, Farhad, Sarvi, Mehdi Nasiri, Azimi, Ebrahim
• Format: Article
• Language: English
• Subjects: Adsorption; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Copper sulfides; cysteine; Diameters; Dyes; Earth and Environmental Science; Ecotoxicology; Energy gap; Environment; Environmental Chemistry; Environmental Health; hot water treatment; Hydrothermal treatment; Ilmenite; Iron; light; Macrostructure; Malachite green; Methylene blue; Nanoparticles; Nanotechnology; Nanotubes; nitrogen; Photocatalysis; Photocatalysts; Quantum dots; Reducing agents; Research Article; surface area; Titanium; Titanium dioxide; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 1614-7499; 0944-1344; 1614-7499
• DOI: 10.1007/s11356-023-29080-w

Titanium dioxide nanotube (TNT) is one of the most widely used photocatalysts. In this research, TNT was prepared by a facile method using ilmenite (FeTiO 3 ) concentrate as the titanium source. For this purpose, iron was leached out from ilmenite using HCl in assistance with the iron powder as the reducing agent to produce pure TiO 2 , where consequently, TNT was produced through hydrothermal treatment of the prepared TiO 2 in an alkaline solution. CuS quantum dots, using the l -cysteine as a linker, were coated on the TNT to improve TNTs’ photocatalytic properties. Characterization was done using XRD, SEM, FESEM, HRTEM, FT-IR, nitrogen sorption, and band gap measurement. The results revealed the formation of TNT with a star-shaped macrostructure as well as, a good dispersion of uniform CuS quantum dots with an average diameter of a few nanometers on the TiO 2 structure. A dye adsorption kinetics study of the TNT and CuS-dopped TNT showed that TNT carries a higher adsorption capacity compared to the CuS-dopped TNT, developed due to its higher surface area and pore volume. Next, the photocatalytic performance (under visible light) of the prepared composite was studied over the methylene blue (MB) and malachite green (MG) dyes, after the determination of the dye adsorption equilibrium point (where the adsorption stops). TNT showed almost no dye degradation while the prepared composite degraded almost 95 % of the dyes as the result of the reduced band gap from 3.21 to 2.67 eV. In this study, for the first time, the TNT was prepared using a mineral source and ilmenite, enhanced in photocatalytic properties, and presented a successful application. Graphical Abstract