Novel and inexpensive Nb2O5/tannin-formaldehyde xerogel composites as substitutes for titanium dioxide in photocatalytic processes
- 34 Downloads
This project studied the preparation of new Nb2O5/tannin-formaldehyde xerogel composites (XTF-wNb) for photocatalytical applications. The choice of tannin biomass and niobium recycled scraps as precursors is aimed at reducing costs and environmental impacts. The composites were characterized by diffuse reflectance spectroscopy (DR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), infrared spectroscopy (IR), and X-ray diffraction (XRD). The photocatalytic properties of the composites were evaluated by methylene blue decomposition. The influence of the catalyst dosage and the initial concentration of dye in the adsorption and photocatalysis processes were studied. The X-ray profiles of the XTF-wNb show the presence of niobic acid in the structure of the materials, proving the presence of the inorganic oxide in the matrix of these composites. The tannin/Nb ratio had a significant influence on the morphology of the formed composites, causing changes in the shape and size of the particles composing each material. All materials have pHPZC < 5. The XTF-24Nb was the most effective photocatalyst, its photocatalytic efficiency superior to the one of titanium dioxide, evidencing the beneficial effect of the xerogel coupling on the photocatalytic properties of the material.
Composites were made using low-cost materials, such as tannin and recycled niobium.
Composites showed photocatalytic activity at all wavelengths tested.
The XTF-24Nb composite presented virtually the same efficiency than that of titanium dioxide.
KeywordsPhotocatalysis Niobium oxide Tannin Xerogel
This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001 and by the São Paulo Research Foundation (FAPESP) (Grants No. 2015/08995-7, No. 2016/04244-0 and No. 2016/20920-5). The authors are grateful to TANAC SA Company, which supplied the black wattle tannin.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 4.Macedo LC, Pauli ED, Zaia DAM, de Santana H (2006) Remediação de águas residuais por Fotocatálise Heterogênea: Estudo dos parâmetros experimentais aplicados a fotocatálise eletroquímica. Semin Ciências Exatas E Tecnológicas 27:11–21. http://www.uel.br/revistas/uel/index.php/semexatas/article/view/1597 CrossRefGoogle Scholar
- 9.Long D, Zhang J, Yang J, Hu Z, Li T, Cheng G, Zhang R, Ling L (2008) Preparation and microstructure control of carbon aerogels produced using m-cresol mediated sol-gel polymerization of phenol and furfural. New Carbon Mater 23:165–170. https://doi.org/10.1016/S1872-5805(08)60020-7 CrossRefGoogle Scholar
- 14.Moraes N, Caetano L, Tiago S, Bastos M, Patrocínio G, Liana T, Rodrigues A (2018) Novel synthetic route for low-cost carbon-modified TiO2 with enhanced visible light photocatalytic activity: carbon content and calcination effects. J Sol-Gel Sci Technol (2018). https://doi.org/10.1007/s10971-018-4700-4
- 16.Hashemzadeh F, Rahimi R, Ghaffarinejad A (2014) Mesoporous nanostructures of Nb2O5 obtained by an EISA route for the treatment of malachite green dye-contaminated aqueous solution under UV and visible light irradiation. Ceram Int 40:9817–9829. https://doi.org/10.1016/j.ceramint.2014.02.072 CrossRefGoogle Scholar
- 17.de Moraes NP, Bacani R, da Silva MLCP, Campos TMB, Thim GP, Rodrigues LA (2018) Effect of Nb/C ratio in the morphological, structural, optical and photocatalytic properties of novel and inexpensive Nb2O5/carbon xerogel composites. Ceram Int 44:6645–6652. https://doi.org/10.1016/j.ceramint.2018.01.073 CrossRefGoogle Scholar
- 19.Dong W, Lee CW, Lu X, Sun Y, Hua W, Zhuang G, Zhang S, Chen J, Hou H, Zhao D (2010) Synchronous role of coupled adsorption and photocatalytic oxidation on ordered mesoporous anatase TiO2-SiO2 nanocomposites generating excellent degradation activity of RhB dye. Appl Catal B Environ 95:197–207. https://doi.org/10.1016/j.apcatb.2009.12.025 CrossRefGoogle Scholar
- 23.de Moraes NP, Silva FN, da Silva MLCP, Campos TMB, Thim GP, Rodrigues LA (2018) Methylene blue photodegradation employing hexagonal prism-shaped niobium oxide as heterogeneous catalyst: effect of catalyst dosage, dye concentration, and radiation source. Mater Chem Phys 214:95–106. https://doi.org/10.1016/j.matchemphys.2018.04.063 CrossRefGoogle Scholar
- 36.Ma X, Chen Y, Li H, Cui X, Lin Y (2015) Annealing-free synthesis of carbonaceous Nb2O5 microspheres by flame thermal method and enhanced photocatalytic activity for hydrogen evolution. Mater Res Bull 66:51–58. https://doi.org/10.1016/j.materresbull.2015.02.005 CrossRefGoogle Scholar
- 45.Joseph CG, Taufiq-Yap YH, Li Puma G, Sanmugam K, Quek KS (2016) Photocatalytic degradation of cationic dye simulated wastewater using four radiation sources, UVA, UVB, UVC and solar lamp of identical power output. Desalin Water Treat 57:7976–7987. https://doi.org/10.1080/19443994.2015.1063463 CrossRefGoogle Scholar
- 48.Liang Z, Cao Y, Qin H, Jia D (2016) Low-heating solid-state chemical synthesis of monoclinic scheelite BiVO4 with different morphologies and their enhanced photocatalytic property under visible light. Mater Res Bull 84:397–402. https://doi.org/10.1016/j.materresbull.2016.08.038 CrossRefGoogle Scholar
- 49.Jones W, Martin DJ, Caravaca A, Beale AM, Bowker M, Maschmeyer T, Hartley G, Masters A (2016) A comparison of photocatalytic reforming reactions of methanol and triethanolamine with Pd supported on titania and graphitic carbon nitride. Appl Catal B Environ 1–7. https://doi.org/10.1016/j.apcatb.2017.01.042
- 56.Hashemzadeh F, Rahimi R, Gaffarinejad A (2013) Photocatalytic degradation of Methylene blue and Rhodamine B dyes by niobium oxide nanoparticles synthesized via hydrothermal method. Int J Appl Chem Sci Res 1:95–102Google Scholar