|Arif Rahman||Department of Chemistry, Faculty of Mathematics & Natural Sciences, Universitas Negeri Jakarta, Rawamangun 13220, Indonesia|
|Muktiningsih Nurjayadi||Department of Chemistry, Faculty of Mathematics & Natural Sciences, Universitas Negeri Jakarta, Rawamangun 13220, Indonesia|
|Rika Wartilah||Department of Chemistry, Faculty of Mathematics & Natural Sciences, Universitas Negeri Jakarta, Rawamangun 13220, Indonesia|
|Eny Kusrini||Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus UI Depok, Depok 16424, Indonesia|
|Eko Adi Prasetyanto||Faculty of Medicine and Health Sciences, Universitas Katolik Indonesia Atma Jaya, Jl. Pluit Raya 2, Jakarta 14440, Indonesia|
|Volkan Degermenci||School of Engineering, University of Warwick, Coventry, CV4 7AL, United Kingdom|
A series of titanium dioxide nanoparticles anchored on mordenite zeolite from an Indonesian natural deposit were prepared by the sol-gel route using a titanium isopropoxide sol as the precursor. Mordenite was incorporated during the sol-gel process by dispersing mordenite powder into the titania sol-gel precursor. The resulting titanium dioxide nanoparticles were in the anatase and rutile form, as confirmed by X-Ray diffraction (XRD) spectroscopy. Diffuse reflectance ultra violet visible (DR-UVVis) spectroscopy analysis indicated a red shift for the band gap energy, which enabled the materials to absorb ultraviolet to visible light. Subjecting the material to photodegradation in a reactor under ultraviolet and visible radiation gave better dye degradation under visible light than ultraviolet irradiation and the yield was proportional with the content of TiO2 nanoparticles incorporated into the zeolite.
Natural zeolite; Photocatalysis; TiO2 photocatalyst
The various applications of photocatalysis based on titanium dioxide is driving rapid growth in this research (Alvarez et al., 2018). One of the prominent applications in this field is the decomposition of organic pollutants. The photocatalytic activity of TiO2 for organic pollutant decomposition is mainly influenced by the crystallinity, particle size, crystal phase, and surface area of the TiO2. A study conducted by Yener et al. (2017) revealed that the anatase form of TiO2, which has a small particle size and high crystallinity, is needed to obtain high photocatalytic activity. However, the presence of a certain amount of TiO2 in the rutile phase can increase photocatalytic activity. This is related to the creation of holes and electrons on the surface of TiO2 for reaction with the substrate and the lifetime of these holes and electrons (Sun et al., 2015).
Many synthesis methods have been developed to obtain TiO2 nanoparticles, such as aerosol pyrolysis, amorphous TiO2 calcination, and colloidal surfactant synthesis (Sun et al., 2015). In general, these methods have the disadvantage of generating products that do not perform sufficiently for photocatalytic applications. However, several methods of synthesis of TiO2 nanoparticles, such as hydrothermal, solvothermal, and microwave methods, can produce TiO2 nanoparticles with high crystallinity and controlled size. Nevertheless, these methods are relatively complicated and require high temperatures and pressures. All three methods require the conversion of the precursors into colloidal forms through the sol-gel process and special equipment to facilitate the TiO2 crystal formation.
In the sol-gel process, metal alkoxides are hydrolyzed by alcohol to metal hydroxide. The sol-gel method has been widely used for the synthesis of oxide materials or other materials, such as SiO2 and PbI2 (Lalena & Cleary, 2005). Using this method, anatase, rutile, and brookite TiO2 nanoparticles have been successfully synthesized (Zhang et al., 2014). Zhang et al. (2018) successfully made rutile and anatase TiO2 nanoparticles, whereas Yener et al. (2017) successfully produced TiO2 nanoparticles in the mordenite structure.
The use of porous material as a host to control the metal oxide particle size has been reported. TiO2, CdO, and ZnO have been successfully synthesized by an ion exchange method using NaY zeolite as a host (Zhao et al., 1996). The use of clinoptilolite natural zeolites as host materials for biogas purification was reported by Kusrini et al. (2016). Efforts to utilize Indonesian natural zeolite for catalysis applications were made by Hidayat et al. (2018). The utilization of zeolite as a carrier in TiO2 synthesis results in smaller particle sizes of TiO2 than can be obtained with pure TiO2 (Hadjltaief et al., 2016), making this zeolite use more desirable in the synthesis of TiO2 nanoparticles. This is because the photocatalytic activity of the TiO2-zeolite system increases when compared to the TiO2 system (Chang et al., 2015).
Zeolite is a porous aluminosilicate material with a unique three-dimensional structure. It is widely used as a catalyst, adsorbent, and ion exchanger. Its pore structure also allows zeolite to be used as a host material. The utilization of zeolite is limited by the high cost of basic materials in industrial scale applications (Maraschi et al., 2014)
In this report, we incorporate TiO2 nanoparticles onto zeolite pores through sol-gel and impregnation processes to enhance the reactivity of the particles. We characterized the catalyst system and examined it for photocatalytic dye degradation under visible light than ultraviolet irradiation.
Taken together, the results of this study indicate that TiO2 nanoparticles synthesized using the impregnated sol-gel method in natural zeolites have a smaller size than the bulk TiO2, which is in the nanometer range. The interaction of TiO2 with zeolite occurs on the external surface of the zeolites, where the TiO2 crystalline phase is a mixture of anatase and rutile. The TiO2-zeolite produced has photocatalytic activity. The photocatalytic activity increases with increasing concentration of the titanium dioxide precursor.
Alvarez, K.M., Alvarado J., Soto, B.S., Hernandez, M.A., 2018. Synthesis of TiO2 Nanoparticles and TiO2-Zeolite Composites and Study of Optical Properties and Structural Characterization. Optik, Volume 169, pp. 137–146
Chatti, R., Rayalu, S.S., Dubey, N., Labhsetwar, N., Devotta, S., 2007. Solar-based Photoreduction of Methyl Orange using Zeolite Supported Photocatalytic Materials. Solar Energy Materials and Solar Cells, Volume 91(2), pp. 180–190
Chang, C.-T., Wang, J.-J.. Ouyang, T., Zhang, Q., Jing., Y.-H., 2015. Photocatalytic Degradation of Acetaminophen in Aqueous Solutions by TiO2/ZSM-5 Zeolite with Low Energy Irradiation. Materials Science & Engineering B, Volume 196, pp. 53–60
Chen, H., Matsumoto, A., Nishimiya, N., & Tsutsumi, K. (1999). Preparation and characterization of TiO2 incorporated Y-zeolite. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 157(1-3), 295–305. doi:10.1016/s0927-7757(99)00052-7
Hadjltaief, H.B, Zina, M., Galvez, M., Da Costa, P., 2016. Photocatalytic Degradation of Methyl Green Dye in Aqueous Solution over Natural Clay-supported ZnO–TiO2 Catalysts. Journal of Photochemistry and Photobiology A: Chemistry, Volume 315, pp. 25–33
Hidayat, A., Mukti, N.I.F., Handoko, B., Sutrisno, B., 2018. Biodiesel Production from Rice Bran Oil over Modified Natural Zeolite Catalyst. International Journal of Technology, Volume 9(2), pp. 400–411
Hoffmann, M.R., Martin, S.T., Choi, W., Bahnemann, D.W., 1995. Environmental Aplications of Semiconductor Photocatalysis, Chemical Reviews, Volume 95(1), 69-96
Kansal, S., Singh, M., Sud, D., 2007. Studies on Photodegradation of Two Commercial Dyes in Aqueous Phase using Different Photocatalysts. Journal of Hazardous Materials, Volume 141(3), pp. 581–590
Kusrini, E., Lukita, M., Gozan, M., Susanto, B.H., Widodo, T.W., Nasution, D.A., Wu, S., Rahman, A., Siregar, Y.D.I., 2016. Biogas from Palm Oil Mill Effluent: Characterization and Removal of CO2 using Modified Clinoptilolite Zeolites in a Fixed-bed Column. International Journal of Technology. Volume 7(4), pp. 625–634
Lalena, J. N., Cleary, D.A., 2005. Principles of Inorganic Material Design. John Wiley & Sons, Inc., USA
Lechert, 1984. The Physical Characterization of Zeolites. In: Ramôa, Ribeiro, F.R., Rodrigues, A.E., Rollmann, L.D, Naccache, C. (eds.). Zeolites: Science and Technology. Springer, Netherlands, pp. 163–164
Li, F.-F., Jiang, Y.-S., Yu, L.-X., Yang, Z.-W., Hou, T.-Y., Sun, S.-M., 2005. Surface Effect of Natural Zeolite (Clinoptilolite) on the Photocatalytic Activity of TiO2. Applied Surface Science, Volume 252(5), pp. 1410–1416
Linsebigler, A.L., Lu, G., Yates, T., 1995. Photocatalysis on TiO2 Surface: Principles, Mechanisms, and Selected Results. Chemical Reviews, Volume 95(3), pp. 735–758
Maraschi, F., Sturini, M., Speltini, A., Pretali, L., Profumo, A., Pastorello, A., Kumar, V., Ferretti, M., Caratto, V., 2014. TiO2-modified Zeolites for Fluoroquinolones Removal from Wastewaters and Reuse after Solar Light Regeneration. Journal of Environmental & Chemical Engineering, Volume 2(4), pp. 2170–2176
Rashed, M.N., El-Amin, A.A., 2007. Photocatalytic Degradation of Methyl Orange in Aqueous TiO2 under Different Solar Irradiation Source. International Journal of Physical Sciences, Volume 2, pp. 73–81
Sayilkan, F., Asilturk, M., Sener, S., Erdemoglu, S., Erdemoglu, M., Sayilkan, H., 2007. Hydrothermal Synthesis, Characterization and Photocatalytic Activity of Nanosized TiO2 Based Catalysts for Rhodamine B Degradation. Turkish Journal of Chemistry, Volume 31, pp. 211–221
Sun, Q., Hu, X.-L., Zheng, S.-L., Sun, Z.-M., Liu, S.-S., Li, H., 2015. Influence of Calcination Temperature on the Structural, Adsorption and Photocatalytic Properties of TiO2 Nanoparticles Supported on Natural Zeolite. Powder Technology, Volume 274, pp. 88–97
Yener, H.B., Y?lmaz, M., Deliismail, Ö., Özkan, S.F., Helvac? ?.?., 2017. Clinoptilolite Supported Rutile TiO2 Composites: Synthesis, Characterization, and Photocatalytic Activity on the Degradation of Terephthalic Acid. Separation and Purification Technology, Volume 173, pp. 17–26
Zhang, G.-G., Song, A.-K., Duan, Y.-W., Zheng, S.-L., 2018. Enhanced Photocatalytic Activity of TiO2/Zeolite Composite for Abatement of Pollutants. Microporous and Mesoporous Materials, Volume 255, pp. 61–68
Zhang, J.., Zhou, P., Liu, J., Yu, J., 2014. New Understanding of the Difference of Photocatalytic Activity among Anatase, Rutile and Brookite TiO2. Physical Chemistry & Chemical Physics, Volume 16(38), pp. 20382–20386
Zhao, X.S., Liu, G.Q., Millar, G.J., 1996. Encapsulation of Transition Metal Species into Zeolites and Molecular Sieves as Redox Catalysts: Part I-Preparation and Characterization of Nanosized TiO2, CdO, and ZnO Semiconductor Particle Anchored in NaY Zeolite. Journal of Porous Materials, Volume 3, pp. 61–66