Cornstalk hydrochar produced by phosphoric acid-assisted hydrothermal carbonization for effective adsorption and photodegradation of norfloxacin

作者：Lan, Yuanwang; Luo, Yidan^*; Yu, Shuohan; Ye, Huiyin; Zhang, Yingshuai; Xue, Mingshan^*; Sun, Qing; Yin, Zuozhu; Li, Xibao; Xie, Chan; Hong, Zhen; Gao, Bin^*

来源：SEPARATION AND PURIFICATION TECHNOLOGY, 2024, 330: 125543.

DOI：10.1016/j.seppur.2023.125543

• Antibiotic
• H3PO4
• Kinetics
• Mechanisms
• NOR

Hydrochars have been widely applied in removing pollutants from aqueous solutions. In this study, hydrochars synthesized by H3PO4-assisted hydrothermal carbonization (HC-xPs) were used to remove norfloxacin (NOR) from water through synergistic adsorption and photodegradation. HC-xPs showed the morphology of carbon microspheres with an average diameter of 0.3 mu m. The specific surface area of the hydrochar carbonized with 5 mol/L H3PO4 (HC-5P) was 11.2 times higher than that of the pristine hydrochar (HC). Furthermore, phosphorus-containing functional groups were introduced to HC-5P, beneficial to its adsorption of NOR. The highest NOR adsorption was achieved on HC-5P with the maximum Langmuir capacity of 69.1 mg g(-1), owing to multiple mechanisms including electrostatic effects, pi-pi interactions, hydrophobic interactions, and hydrogen bonding. Compared with HC, HC-5P also demonstrated increased visible light absorption capacity. The first-order rate constant of HC-5P on combined adsorption and photodegradation of NOR was 12.0 times of HC. The photodegradation intermediates were identified by HPLC-MS to understand NOR degradation pathways. This work can be extended to the preparation of low-cost and highly efficient hydrochars for adsorption and photodegradation of pollutants in water.

• 单位
  南昌大学; 南昌航空大学