Larger Adsorption Effect of Fluoride than Phosphate on Phenol Degradation over the Irradiated Anatase TiO2 and Pt/TiO2
Received date: 2019-01-04
Online published: 2019-03-05
Supported by
Project supported by the Funds for Creative Research Group of NSFC (No. 21621005).
It is known that fluoride and phosphate in aqueous solution can accelerate the photocatalytic degradation of phenol over anatase or P25 TiO2. But the mechanism still remains under debate. In this work, an anion-free anatase TiO2 is prepared, followed by deposition with 0.52 wt% Pt (Pt/TiO2). Reaction was performed in aqueous solution at initial pH 5.2, where 99% of anions were in the form of F- or H2PO4-. On the addition of 0.1~30 mmol/L anions, the rate constants of phenol degradation (kobs) were all increased, confirming the positive effect of fluoride and phosphate, respectively. Interestingly, there was a linear relationship between the increase of kobs and the amounts of anion adsorption, the slope of which became larger in the order of fluoride>phosphate, and Pt/TiO2>TiO2. These observations indicate that the positive effect of anions originates from the adsorbed anions on solid, and that fluoride was more active than phosphate. A (photo)electrochemical measurement showed that fluoride and phosphate were negative and positive, respectively, to O2 reduction, but they were all beneficial to phenol oxidation. Furthermore, in the presence of fluoride and phosphate, the flat band potentials of TiO2 were shifted by -159 and 89 mV, respectively. The former favors orbital overlapping of phenol with TiO2 valence band, and the latter favors orbital overlapping of O2 with TiO2 conduction band, all of which promotes the interfacial charge transfers. Since inorganic anions are widely present, this result would benefit the mechanism study of a semiconductor photocatalyis and its application. As a reference, pure anatase was prepared from the hydrolysis of tetrabutyl titanate, followed by calcination in air at 400℃ for 2 h. The solid was then deposited with Pt, produced in situ from the photocatalytic reduction of H2PtCl6 in the presence of methanol. Solid was characterized with X-ray diffraction, N2 adsorption, Raman, and X-ray photoelectron spectroscopy. After Pt deposition, anatase phase remained unchanged, but the solid pores were blocked by a mixture of Pt and PtO2. Photoreactions were performed at room temperature under UV light at wavelengths equal to and longer than 320 nm. Organic compounds and inorganic anions were quantitatively analyzed with a high performance liquid and ionic chromatography, respectively. (Photo)electrochemical measurement was performed in a three-electrode compartment, where a Pt gauze was used as counter electrode, and a AgCl/Ag as reference electrode.
Key words： anatase TiO2; fluoride; phosphate; adsorption; photoelectrocatalysis; charge transfer
Liu Shengwei , Zhao Jianjun , Xu Yiming . Larger Adsorption Effect of Fluoride than Phosphate on Phenol Degradation over the Irradiated Anatase TiO2 and Pt/TiO2[J]. Acta Chimica Sinica, 2019 , 77(4) : 351 -357 . DOI: 10.6023/A19010009
[1] Wu, J. J.; Ji, Z. Y.; Shen, X. P.; Miao, X. L.; Xu, K. Q. Acta Chim. Sinica 2017, 75, 1207.(吴佳佳, 季振源, 沈小平, 缪绪立, 徐克强, 化学学报, 2017, 75, 1207.)
[2] Du, P. J.; Su, T. M.; Luo, X.; Zhou, X. T.; Qin, Z. Z.; Ji, H. B.; Chen, J. H. Chin. J. Chem. 2018, 36, 538.
[3] Chai, Y. Y.; Liu, Q. Q.; Zhang, L.; Ren, J.; Dai, W. L. Chin. J. Chem. 2017, 35, 173.
[4] Zhang, F. L.; Duan, F.; Ding, Z. G.; Chen, M. Q. Chin. J. Chem. 2017, 35, 226.
[5] Hoffmann, M.; Martin, S.; Choi, W.; W. Bahnemann, D. W. Chem. Rev. 1995, 95, 69.
[6] Tachikawa, T.; Fujitsuka, M.; Majima, T. J. Phys. Chem. C 2007, 111, 5259.
[7] Zielińska-Jurek, A.; Zaleska, A. Catal. Today 2014, 230, 104.
[8] Chen, K. T.; Lu, C. S.; Chang, T. H.; Lai, Y. Y.; Chang, T. H.; Wu, C. W.; Chen, C. C. J. Hazard. Mater. 2010, 174, 598.
[9] Chiang, K.; Amal, R.; Tran, T. J. Mol. Catal. A:Chem. 2003, 193, 285.
[10] Kumar, A.; Mathur, N. J. Colloid Interf. Sci. 2006, 300, 244.
[11] Lv, K. L.; Li, X. F.; Deng, K. J.; Sun, J.; Li, X. H.; Li, M. Appl.Catal. B:Environ 2010, 95, 383.
[12] Minero, C.; Mariella, G.; Maurino, V.; Pelizzetti, E. Langmuir 2000, 16, 2632.
[13] Minero, C.; Mariella, G.; Maurino, V.; Vione, D.; Pelizzetti, E. Langmuir 2000, 16, 8964.
[14] Vohra, M. S.; Kim, S.; Choi, W. J. Photochem. Photobiol., A:Chem. 2003, 160, 55.
[15] Park, H.; Choi, W. J. Phys. Chem. B 2004, 108, 4086.
[16] Yu, J. C.; Zhang, L. Z.; Zheng, Z.; Zhao, J. C. Chem. Mater. 2003, 15, 2280.
[17] Zhao, D.; Chen, C. C.; Wang, Y. F.; Ji, H. W.; Ma, W. H.; Zang, L.; Zhao, J. C. J. Phys. Chem. C 2008, 112, 5993.
[18] Zhang, X.; Xiong, X. Q.; Xu, Y. M. RSC Adv. 2016, 6, 61830.
[19] Xiong, X. Q.; Xu, Y. M. J. Phys. Chem. C 2016, 120, 3906.
[20] Xiong, X. Q.; Zhang, X.; Xu, Y. M. J. Phys. Chem. C 2016, 120, 25689.
[21] Mathpal, M. C.; Tripathi, A. K.; Singh, M. K; Gairola, S. P.; Pandey, S. N.; Agarwal, A. Chem. Phys. Lett. 2013, 555, 182.
[22] Choi, H. C.; Jung, Y. M.; Kim, S. B. Vib. Spectrosc. 2005, 37, 33.
[23] Li, F. B.; Li, X. Z. Chemosphere 2002, 48, 1103.
[24] Nie, L. H.; Yu, J. G.; Li, X. Y.; Cheng, B.; Liu, G.; Jaroniec, M. Environ. Sci. Technol. 2013, 47, 2777.
[25] Yu, J. G.; Qi, L. F.; Jaroniec, M. J. Phys. Chem. C 2010, 114, 13118.
[26] Vorontsov, A. V.; Savinov, E. N.; Zhensheng, J. J. Photochem. Photobiol., A:Chem. 1999, 125, 113.
[27] Cao, Y.; Jing, L.; Shi, X.; Luan, Y.; Durrant, J. R.; Tang, J.; Fu, H. Phys. Chem. Chem. Phys. 2012, 14, 8530.
[28] Minella, M.; Maurino, V.; Minero, C.; Pelizzetti, E. J. Nanosci. Nanotechnol. 2015, 15, 3348.
[29] Nelson, B. P.; Candal, R.; Corn, R. M.; Anderson, M. A. Langmuir 2000, 16, 6094.
[30] Li, S. F.; Ye, G. L.; Chen, G. Q. J. Phys. Chem. C 2009, 113, 4031.
[31] Kim, J.; Lee, C. W.; Choi, W. Environ. Sci. Technol. 2010, 44, 6849.
[32] Barbé, C. J.; Arendse, F.; Comte, P.; Jirousek, M.; Lenzmann, F.; Shklover, V.; Grätzel, M. J. Am. Ceram. Soc. 2005, 80, 3157.
[33] Topoglidis, E.; Lutz, T.; Willis, R. L.; Barnett, C. J.; Cass, A. E. G.; Durrant, J. R. Faraday Discuss. 2000, 116, 35.
[34] Willis, R. L.; Olson, C.; O'Regan, B.; Lutz, T.; Nelson, J.; Durrant, J. R. J. Phys. Chem. B 2002, 106, 7605.
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