Enhanced Visible-light Photocatalytic Activity of g-C₃N₄/Nitrogen-doped Graphene Quantum Dots/TiO₂ Ternary Heterojunctions for Ciprofloxacin Degradation with Narrow Band Gap and High Charge Carrier Mobility

Abstract

Limited visible-light absorption and high recombination rate of photogenerated charges are two main drawbacks in g-C₃N₄-based photocatalysts. To solve these problems, g-C₃N₄/nitrogen-doped graphene quantum dots (NGQDs)/TiO₂ ternary heterojunctions were facilely prepared via a one-step calcining method. The morphology, structure, optical and electrochemical properties of g-C₃N₄/NGQDs/TiO₂ were characterized and explored. The optimal g-C₃N₄/NGQDs/TiO₂ composite exhibits enhanced photocatalytic degradation performance of ciprofloxacin (CIP) compared with the as-prepared g-C₃N₄, TiO₂(P25) and g-C₃N₄/TiO₂ heterojunction under visible light irradiation. The apparent rate constant of the composite is around 6.43, 4.03 and 2.30 times higher than those of g-C₃N₄, TiO₂ and g-C₃N₄/TiO₂, respectively. The enhanced photocatalytic efficiency should be mainly attributed to the improvement of light absorption and charge separation and transfer efficiency, originating from the narrow band gap and high charge carrier mobility. The active species trapping experiments results showed that the h⁺ and ^·O₂ ⁻ were the main active species in the degradation process. A possible photocatalytic reaction mechanism of the g-C₃N₄/NGQDs/TiO₂ composite for the enhanced degradation of CIP under visible light irradiation was also proposed.

Keywords

g-C₃N₄/NGQDs/TiO₂ / Heterojunction / Photocatalysis / Antibiotic ciprofloxacin

References

[1] Välitalo P, Kruglova A, Mikola A, Vahala R. Int. J. Hyg. Environ. Health, 2017, 220: 558.

[2] Lin J-S, Pan H-Y, Liu S-M, Lai H-T. J. Environ. Sci. Heal. B, 2010, 45: 456.

[3] Li D, Shi W. Chinese J. Catal., 201, 37: 792.

[4] Liao G, Gong Y, Zhang L, Gao H, Yang G-J, Fang B. Energ. Environ. Sci., 2019, 12: 2080.

[5] Reddy K R, Reddy C H V, Nadagouda M N, Shetti N P, Jaesool S, Aminabhavi T M. J. Environ. Manage., 2019, 238: 25.

[6] Zada A, Qu Y, Ali S, Sun N, Lu H, Yan R, Zhang X, Jing L. J. Hazard. Mater., 2018, 342: 715.

[7] Schneider J, Matsuoka M, Takeuchi M, Zhang J, Horiuchi Y, Anpo M, Bahnemann D W. Chem. Rev., 2014, 114: 9919.

[8] Xu Y, Luo Y, Qian Q, Huang B, Chen Q. Opt. Mater., 2017, 72: 691.

[9] Chen P, Wang F, Zhang Q, Su Y, Shen L, Yao K, Chen Z-F, Liu Y, Cai Z, Lv W, Liu G. Chemosphere, 2017, 172: 193.

[10] Wang H, Li J, Ma C, Guan Q, Lu Z, Huo P, Yan Y. Appl. Surf. Sci., 2015, 329: 17.

[11] Yang Z, Yan J, Lian J, Xu H, She X, Li H. ChemistrySelect, 201, 1: 5679.

[12] Sheng Y, Wei Z, Miao H, Yao W, Li H, Zhu Y. Chem. Eng. J., 2019, 370: 287.

[13] Acharya R, Parida K. J. Environ. Chem. Eng., 2020, 8: 103896.

[14] Zhang Z, Zhang J, Chen N, Qu L. Energ. Environ. Sci., 2012, 5: 8869.

[15] Wang Z, Zeng H, Sun L. J. Mater. Chem. C, 2015, 3: 1157.

[16] Liu J, Xu H, Xu Y, Song Y, Lian J, Zhao Y, Wang L, Huang L, Ji H, Li H. Appl. Catal. B: Environ., 2017, 207: 429.

[17] Xu T, Wang D, Dong L, Shen H, Lu W, Chen W. Appl. Catal. B: Environ., 2019, 244: 96.

[18] Yan M., Zhu F., Gu W., Sun L., Shi W., Hua Y., RSC Adv., 2016, 6

[19] Tang L, Ji R, Li X, Teng K S, Lau S P. J. Mater. Chem. C, 2013, 7: 4908.

[20] Mou Z, Lu C, Yu K, Wu H, Zhang H, Sun J, Zhu M, Goh M C. Energy Technol., 2019, 7: 1800589.

[21] Qu D, Zheng M, Du P, Zhou Y, Zhang L, Li D, Tan H, Zhao Z, Xie Z, Sun Z. Nanoscale, 2013, 5: 12272.

[22] Guo F, Chen J, Zhao J, Chen Z, Xia D, Zhan Z, Wang Q. Chem. Eng. J., 2020, 386: 124014.

[23] Zhang L, Xi Z, Xing M, Zhang J. Int. J. Hydrogen Energ., 2013, 38: 9169.

[24] Yu J, Wang S, Low J, Xiao W. Phys. Chem. Chem. Phys., 2013, 75: 16883.

[25] Pan J, You M, Chi C, Dong Z, Wang B, Zhu M, Zhao W, Song C, Zheng Y, Li C. Int. J. Hydrogen Energ., 2018, 43: 6586.

[26] He J, Sun H, Indrawirawan S, Duan X, Tade M O, Wang S. J. Colloid Interf. Sci., 2015, 456: 15.

[27] Zhang M, Lai C, Li B, Huang D, Zeng G, Xu P, Qin L, Liu S, Liu X, Yi H, Li M, Chu C, Chen Z. J. Catal., 2019, 369: 469.

[28] Ming L, Yue H, Xu L, Chen F. J. Mater. Chem. A, 2014, 2: 19145.

[29] Qiu X, Zhao Y, Burda C. Adv. Mater., 2007, 19: 3995.

[30] Zhong R, Zhang Z, Yi H, Zeng L, Tang C, Huang L, Gu M. Appl. Catal. B: Environ., 2018, 237: 1130.

[31] Zhong R, Zhang Z, Luo S, Zhang Z C, Huang L, Gu M. Catal. Sci. Technol., 2019, 9: 75.

[32] Fu J, Yu J, Jiang C, Cheng B. Adv. Energy Mater., 2018, 8: 1701503.

[33] Zhao W, Hao N, Zhang G, Ma A, Chen W, Zhou H, Yang D, Xu B B, Kong J. Chem. Res. Chinese Universities, 2020, 36(6): 1271.

[34] Li C, Sun Z, Zhang W, Yu C, Zheng S. Appl. Catal. B: Environ., 2018, 220: 272.

[35] Ding Y, Gao Y, Li Z. Appl. Surf. Sci., 2018, 462: 255.

[36] Che H, Liu C, Hu W, Hu H, Li J, Dou J, Shi W, Li C, Dong H. Catal. Sci. Technol., 2018, 8: 622.

[37] Yan M, Hua Y, Zhu F, Gu W, Jiang J, Shen H, Shi W. Appl. Catal. B: Environ., 2017, 202: 518.

[38] Wang B, Ding Y, Deng Z, Li Z. Chinese J. Catal., 2019, 40: 335.

[39] Zhu M, Liu Q, Chen W, Yin Y, Ge L, Li H, Wang K. ACS Appl. Mater. Inter., 2017, 9: 38832.

[40] Wang B, Deng Z, Fu X, Li Z. J. Mater. Chem. A, 2018, 6: 19735.

[41] Asadzadeh-Khaneghah S, Habibi-Yangjeh A, Yubuta K. J. Am. Ceram. Soc., 2019, 102: 1435.