Photocatalytic Degradation of 4-Chlorophenol by Gd-Doped β-Bi₂O₃ Under Visible Light Irradiation

Abstract

Chlorophenols are known as persistent organic pollutants. Therefore, research on the removal of chlorophenols has attracted widespread attention. Herein, the photocatalytic degradation of 4-chlorophenol by Gd-doped β-Bi₂O₃ under visible light irradiation was studied. The results showed that Gd-doped β-Bi₂O₃ materials are efficient catalysts for the photocatalytic degradation of chlorophenols, and 2%(atomic fraction) Gd-doped β-Bi₂O₃ exhibits the highest photocatalytic activity for 4-chlorophenol degradation, because doping an appropriate amount of Gd³⁺ ions can effectively reduce the recombination rate of the photogenerated e^‒/h⁺ pairs and then enhance the photocatalytic performance. When the reaction was carried out at 25 °C for 6 h using the 2% Gd-doped β-Bi₂O₃ micro/nano materials of 200 mg and at air flow rate of 40 mL/min, the degradation rate of 4-chlorophenol reached 92.3%. Additionally, based on the analysis of the products, it was speculated that the dominant photocatalytic degradation mechanism of 4-chlorophenol by Gd-doped β-Bi₂O₃ under visible light irradiation is an oxidative process involving an attack by the hydroxyl radical.

Keywords

Bi₂O₃ / Doping / Photocatalysis / 4-Chlorophenol

References

[1] Huang Z. D., Wen M., Wu Q. S., Zhang Y. Q., Fang H., Chen H. X. J. Colloid Interface Sci., 2015, 460: 230.

[2] Vallejo M., San Román M. F., Ortiz I. Environ. Sci. Technol., 2013, 47(21): 12400.

[3] Shen W. J., Mu Y., Wang B. N., Ai Z. H., Zhang L. Z. Appl. Surf. Sci., 2017, 393: 316.

[4] Nguyen A. T., Juang R. S. J. Environ. Manage., 2015, 147: 271.

[5] Chauhan R., Srivastava V. C., Hiwarkar A. D. J. Taiwan Inst. Chem. Eng., 2016, 69: 106.

[6] Pozan G. S., Kambur A. Appl. Catal. B: Environ., 2013, 129: 409.

[7] Luo X. C., Zhu G. Q., Peng J. H., Wei X. M., Hojamberdiev M., Jin L., Liu P. Appl. Surf. Sci., 2015, 351: 260.

[8] Zhang L. S., Wang W. Z., Yang J., Chen Z. G., Zhang W. Q., Zhou L., Liu S. W. Ap.pl. Catal. A: General, 2006, 308: 105.

[9] Chai S.Y., Kim Y. J., Jung M. H., Chakraborty A. K., Jung D., Lee W. I. J. Catal., 2009, 262(1): 144.

[10] Xie J. M., Lv X. M., Chen M., Zhao G. Q., Song Y. Z., Lu S. S. Dyes Pigm., 2008, 77(1): 43.

[11] Wu X. H., Qin W., Li L., Guo Y., Xie Z. Y. Catal. Commun., 2009, 10(5): 600.

[12] Li J. Z., Zhong J. B., Zeng J., Feng F. M., He J. J. Mat. Sci. Semicon. Proc., 2013, 16(2): 379.

[13] Li L. Z., Yan B. J. Non-Cryst. Solids, 2009, 355(13): 776.

[14] Fang J., Bao H. Z., He B., Wang F., Si D. J., Jiang Z. Q., Pan Z. Y., Wei S. Q., Huang W. X. J. Phys. Chem. C, 2007, 111(51): 19078.

[15] Hu L. M., Dong S. Y., Li Q. L., Feng J. L., Pi Y. Q., Liu M. L., Sun J. Y., Sun J. H. J. Alloy. Compd., 2015, 633: 256.

[16] Liu X., Kang Y. Mater. Lett., 2016, 164: 229.

[17] Sher Shah M. S. A., Park A. R., Zhang K., Park J. H., Yoo P. J. ACS Appl. Mater. Inter., 2012, 4(8): 3893.

[18] He G. P., Xing C. L., Xiao X., Hu R. P., Zuo X. X., Nan J. M. Appl. Catal. B: Environ., 2015.

[19] Xu J. J., Chen M. D., Fu D. G. Trans. Nonferrous Met. Soc. China, 2011, 21(2): 340.

[20] Selvam N. C. S., Narayanan S., Kennedy L. J., Vijiaya J. J., J. Environ. Sci., 2013, 25(10): 2157.

[21] Palanisamy B., Babu C. M., Sundaravel B., Anandan S., Murugesan V. J. Hazard. Mater., 2013.

[22] Ki S. J., Jeon K. J., Park Y. K., Jeong S., Lee H., Jung S. C. Catal. Today, 2017.

[23] Yue B., Zhou Y., Xu J. Y., Wu Z. Z., Zhang X., Zou Y. F., Jin S. L. Environ. Sci. Technol., 2002, 36(6): 1325.