TiO2 Nanowires as Efficient Heterogeneous Photocatalysts for Waste-Water Treatment
One-dimensional (1D) nanostructures like nanowires, nanotubes, and nanorods find variety of practical application owing to their unique physico-chemical properties. In this work, TiO2 nanowires were synthesized by direct oxidation of titanium particles in a unique microwave plasma jet reactor. The prepared TiO2 nanowires manifested the flexible features, and were characterized by using X-ray diffraction, Brunauer-Emmett-Teller (BET) surface area analyzer, UV-Visible and FTIR spectrophotometers, Scanning electron microscope, and Transmission electron microscope. Further, the photodegradation efficiency of these nanowires were tested against toxic organic dye like methylene blue (MB) and the results were compared with the commercial TiO2. It was found that TiO2 nanowires exhibited superior photocatalytic performance (89%) as compared to commercial TiO2 (75%) after 60 min of reaction. This is attributed to the lower recombination rate and increased interfacial charge transfer in TiO2 nanowire. Pseudo-first order kinetic modelling performed with the experimental results revealed that the rate constant of photodegradation in case of TiO2 nanowire was 1.3 times higher than that of commercial TiO2. Superoxide radical (O2˙−) was found to be the major contributor in the photodegradation mechanism. Based on the trapping experiments, a plausible mechanism of the photocatalytic reaction is discussed.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.3566399Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 385
References:Y. Tang, H. Ren, J. Huang, "Synthesis of porous TiO2 nanowires and their photocatalytic properties", Front. Optoelectron. 10 (2017) 395–401. doi:10.1007/s12200-017-0735-3.
 C.H. Nguyen, C.C. Fu, R.S. Juang, "Degradation of methylene blue and methyl orange by palladium-doped TiO2 photocatalysis for water reuse: Efficiency and degradation pathways", J. Clean. Prod. 202 (2018) 413–427. doi:10.1016/j.jclepro.2018.08.110.
 Y.C. Yao, X.R. Dai, X.Y. Hu, S.Z. Huang, Z. Jin, "Synthesis of Ag-decorated porous TiO2 nanowires through a sunlight induced reduction method and its enhanced photocatalytic activity", Appl. Surf. Sci. 387 (2016) 469–476. doi:10.1016/j.apsusc.2016.06.130.
 L. Soto-Vázquez, F. Rolón-Delgado, K. Rivera, M.C. Cotto, J. Ducongé, C. Morant, S. Pinilla, F.M. Márquez-Linares, "Catalytic use of TiO2 nanowires in the photodegradation of Benzophenone-4 as an active ingredient in sunscreens", J. Environ. Manage. 247 (2019) 822–828. doi:10.1016/j.jenvman.2019.07.005.
 D. Cheng, Y. Li, L. Yang, S. Luo, L. Yang, X. Luo, Y. Luo, T. Li, J. Gao, D.D. Dionysiou, "One–step reductive synthesis of Ti3+ self–doped elongated anatase TiO2 nanowires combined with reduced graphene oxide for adsorbing and degrading waste engine oil", J. Hazard. Mater. 378 (2019) 120752. doi:10.1016/j.jhazmat.2019.120752.
 H. Bin Wu, H.H. Hng, X.W.D. Lou, "Direct synthesis of anatase TiO2 nanowires with enhanced photocatalytic activity", Adv. Mater. 24 (2012) 2567–2571. doi:10.1002/adma.201200564.