Effect of pH-Dependent Homo/Heteronuclear CAHB on Adsorption and Desorption Behaviors of Ionizable Organic Compounds on Carbonaceous Materials

Xiaoyun Li; Jinlong Zhang; Yaofeng Jin; Yifan Liu; Nana Li; Yue Wang; Cong Du; Zhijing Xue; Nan Zhang; Qin Chen

doi:10.3390/ijerph191912118

Effect of pH-Dependent Homo/Heteronuclear CAHB on Adsorption and Desorption Behaviors of Ionizable Organic Compounds on Carbonaceous Materials

Int J Environ Res Public Health. 2022 Sep 25;19(19):12118. doi: 10.3390/ijerph191912118.

Authors

Xiaoyun Li^{1

2}, Jinlong Zhang¹, Yaofeng Jin¹, Yifan Liu¹, Nana Li¹, Yue Wang¹, Cong Du¹, Zhijing Xue¹, Nan Zhang³, Qin Chen⁴

Affiliations

¹ Department of Environmental Science, School of Geography and Tourism, Shaanxi Normal University, Xi'an 710119, China.
² International Joint Research Centre of Shaanxi Province for Pollutants Exposure and Eco-Environmental Health, Xi'an 710119, China.
³ Environmental Protection Department of Mahe Town, Yuyang District, Yulin 719000, China.
⁴ Northwest Land and Resource Research Center, Shaanxi Normal University, Xi'an 710119, China.

Abstract

Herein, the adsorption/desorption behaviors of benzoic acid (BA) and phthalic acid (PA) on three functionalized carbon nanotubes (CNTs) at various pH were investigated, and the charge-assisted H-bond (CAHB) was verified by DFT and FTIR analyses to play a key role. The results indicated that the adsorption order of BA and PA on CNTs was different from K_ow of that at pH 2.0, 4.0, and 7.0 caused by the CAHB interaction. The strength of homonuclear CAHB (≥78.96 kJ·mol^-1) formed by BA/PA on oxidized CNTs is stronger than that of heteronuclear CAHB formed between BA/PA and amino-functionalized CNTs (≤51.66 kJ·mol^-1). Compared with the heteronuclear CAHB (Hysteresis index, HI ≥ 1.47), the stronger homonuclear CAHB leads to clearly desorption hysteresis (HI ≥ 3.51). Additionally, the contribution of homonuclear CAHB (≥52.70%) was also greater than that of heteronuclear CAHB (≤45.79%) at pH 7.0. These conclusions were further confirmed by FTIR and DFT calculation, and the crucial evidence of CAHB formation in FTIR was found. The highlight of this work is the identification of the importance and difference of pH-dependent homonuclear/heteronuclear CAHB on the adsorption and desorption behaviors of ionizable organic compounds on carbonaceous materials, which can provide a deeper understanding for the removal of ionizable organic compounds by designed carbonaceous materials.

Keywords: carbonaceous materials; density functional theory; desorption hysteresis; hydrogen bond; ionizable organic chemicals.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Benzoic Acid
Hydrogen-Ion Concentration
Nanotubes, Carbon* / chemistry
Organic Chemicals / chemistry

Substances

Nanotubes, Carbon
Organic Chemicals
Benzoic Acid

Grants and funding

This work was supported by the National Natural Science Foundation of China (42177202, 41703093, 41907148), Key R&D project of Shaanxi Province (2022NY-054), the Fundamental Research Funds for the Central University (GK202103138, 2021CSLY015, GK202103128).